Fix: Fencing: Prevent sending SIGTERM to stonithd when stointh operation timed out

__[ problem point ]__
When stonith operation is executed and

```
UID        PID  PPID  PGID   SID  C STIME TTY          TIME CMD
root     18143     1 18143 18143  2 16:05 ?        00:00:02 corosync
root     18149     1 18149 18149  0 16:05 ?        00:00:00 /usr/sbin/pacemakerd -f
root     18152 18149 18152 18152  0 16:05 ?        00:00:00 /usr/libexec/pacemaker/stonithd
root     18153 18149 18153 18153  0 16:05 ?        00:00:00 /usr/libexec/pacemaker/lrmd
root     18372 18152 18152 18152  1 16:06 ?        00:00:00 /usr/bin/perl /usr/sbin/fence_legacy
root     18373 18372 18152 18152  0 16:06 ?        00:00:00 stonith -t external/libvirt.NG1 -E -T reset dev1
root     18378 18373 18152 18152  0 16:06 ?        00:00:00 /bin/sh /usr/lib64/stonith/plugins/external/libvirt.NG1 reset dev1
root     18382 18378 18152 18152  0 16:06 ?        00:00:00 sleep 135
991      18151 18149 18151 18151  0 16:05 ?        00:00:00 /usr/libexec/pacemaker/cib
991      18154 18149 18154 18154  0 16:05 ?        00:00:00 /usr/libexec/pacemaker/attrd
991      18155 18149 18155 18155  0 16:05 ?        00:00:00 /usr/libexec/pacemaker/pengine
991      18156 18149 18156 18156  0 16:05 ?        00:00:00 /usr/libexec/pacemaker/crmd
```
it timed out, SIGTERM is sent also to stonithd. As a result, __stonithd does unnecessary restart__.

```
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: st_child_term: Child 18372 timed out, sending SIGTERM
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: crm_signal_dispatch: Invoking handler for signal 15: Terminated
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: stonith_shutdown: Terminating with  2 clients
Aug  1 16:07:25 dev2 cib[18151]:     info: crm_client_destroy: Destroying 0 events
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: cib_connection_destroy: Connection to the CIB closed.
Aug  1 16:07:25 dev2 lrmd[18153]:    error: crm_ipc_read: Connection to stonith-ng failed
Aug  1 16:07:25 dev2 lrmd[18153]:    error: mainloop_gio_callback: Connection to stonith-ng[0xfed890] closed (I/O condition=17)
Aug  1 16:07:25 dev2 lrmd[18153]:    error: stonith_connection_destroy_cb: LRMD lost STONITH connection
Aug  1 16:07:25 dev2 lrmd[18153]:    error: stonith_connection_failed: STONITH connection failed, finalizing 2 pending operations.
Aug  1 16:07:25 dev2 crmd[18156]:    error: process_lrm_event: LRM operation f1-1_monitor_3600000 (call=31, status=4, cib-update=45, confirmed=false) Error
Aug  1 16:07:25 dev2 crmd[18156]:    error: process_lrm_event: LRM operation f1-2_monitor_3600000 (call=37, status=4, cib-update=46, confirmed=false) Error
Aug  1 16:07:25 dev2 crmd[18156]:     info: abort_transition_graph: process_graph_event:520 - Triggered transition abort (complete=0, node=dev2, tag=lrm_rsc_op, id=f1-1_last_failure_0, magic=4:1;18:2:0:20d90530-b60e-47f4-9180-465e3d41de54, cib=0.8.25) : Old event
Aug  1 16:07:25 dev2 crmd[18156]:  warning: update_failcount: Updating failcount for f1-1 on dev2 after failed monitor: rc=1 (update=value++, time=1375340845)
Aug  1 16:07:25 dev2 attrd[18154]:     info: find_hash_entry: Creating hash entry for fail-count-f1-1
Aug  1 16:07:25 dev2 attrd[18154]:     info: attrd_local_callback: Expanded fail-count-f1-1=value++ to 1
Aug  1 16:07:25 dev2 attrd[18154]:   notice: attrd_trigger_update: Sending flush op to all hosts for: fail-count-f1-1 (1)
Aug  1 16:07:25 dev2 crmd[18156]:     info: process_graph_event: Detected action (2.18) f1-1_monitor_3600000.31=unknown error: failed
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: crm_client_destroy: Destroying 0 events
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_modify operation for section status: OK (rc=0, origin=local/crmd/45, version=0.8.25)
Aug  1 16:07:25 dev2 crmd[18156]:     info: abort_transition_graph: process_graph_event:520 - Triggered transition abort (complete=0, node=dev2, tag=lrm_rsc_op, id=f1-2_last_failure_0, magic=4:1;20:2:0:20d90530-b60e-47f4-9180-465e3d41de54, cib=0.8.26) : Old event
Aug  1 16:07:25 dev2 crmd[18156]:  warning: update_failcount: Updating failcount for f1-2 on dev2 after failed monitor: rc=1 (update=value++, time=1375340845)
Aug  1 16:07:25 dev2 crmd[18156]:     info: process_graph_event: Detected action (2.20) f1-2_monitor_3600000.37=unknown error: failed
Aug  1 16:07:25 dev2 crmd[18156]:    error: crm_ipc_read: Connection to stonith-ng failed
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: crm_client_destroy: Destroying 0 events
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_modify operation for section status: OK (rc=0, origin=local/crmd/46, version=0.8.26)
Aug  1 16:07:25 dev2 crmd[18156]:    error: mainloop_gio_callback: Connection to stonith-ng[0x14181d0] closed (I/O condition=17)
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: qb_ipcs_us_withdraw: withdrawing server sockets
Aug  1 16:07:25 dev2 crmd[18156]:     crit: tengine_stonith_connection_destroy: Fencing daemon connection failed
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_query operation for section //cib/status//node_state[@id='3232261523']//transient_attributes//nvpair[@name='fail-count-f1-1']: No such device or address (rc=-6, origin=local/attrd/9, version=0.8.26)
Aug  1 16:07:25 dev2 crmd[18156]:   notice: fail_incompletable_stonith: Failing action 27 (27): STONITHd terminated
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_query operation for section /cib: OK (rc=0, origin=local/attrd/10, version=0.8.26)
Aug  1 16:07:25 dev2 attrd[18154]:   notice: attrd_perform_update: Sent update 11: fail-count-f1-1=1
Aug  1 16:07:25 dev2 attrd[18154]:     info: find_hash_entry: Creating hash entry for last-failure-f1-1
Aug  1 16:07:25 dev2 attrd[18154]:   notice: attrd_trigger_update: Sending flush op to all hosts for: last-failure-f1-1 (1375340845)
Aug  1 16:07:25 dev2 crmd[18156]:  warning: fail_incompletable_stonith: STONITHd failure resulted in un-runnable actions
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: main: Done
Aug  1 16:07:25 dev2 stonith-ng[18152]:     info: crm_xml_cleanup: Cleaning up memory from libxml2
Aug  1 16:07:25 dev2 crmd[18156]:     info: abort_transition_graph: fail_incompletable_stonith:74 - Triggered transition abort (complete=0, node=, tag=crm_event, id=27, magic=NA) : Stonith failure
Aug  1 16:07:25 dev2 crmd[18156]:     info: abort_transition_graph: te_update_diff:172 - Triggered transition abort (complete=0, node=dev2, tag=nvpair, id=status-3232261523-fail-count-f1-1, name=fail-count-f1-1, value=1, magic=NA, cib=0.8.27) : Transient attribute: update
Aug  1 16:07:25 dev2 crmd[18156]:   notice: run_graph: Transition 4 (Complete=1, Pending=0, Fired=0, Skipped=9, Incomplete=0, Source=/var/lib/pacemaker/pengine/pe-warn-1.bz2): Stopped
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_modify operation for section status: OK (rc=0, origin=local/attrd/11, version=0.8.27)
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_query operation for section //cib/status//node_state[@id='3232261523']//transient_attributes//nvpair[@name='last-failure-f1-1']: No such device or address (rc=-6, origin=local/attrd/12, version=0.8.27)
Aug  1 16:07:25 dev2 pacemakerd[18149]:     info: pcmk_child_exit: Child process stonith-ng (18152) exited: OK (0)
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_query operation for section /cib: OK (rc=0, origin=local/attrd/13, version=0.8.27)
Aug  1 16:07:25 dev2 pacemakerd[18149]:   notice: pcmk_process_exit: Respawning failed child process: stonith-ng
Aug  1 16:07:25 dev2 pacemakerd[18149]:     info: start_child: Forked child 18398 for process stonith-ng
Aug  1 16:07:25 dev2 attrd[18154]:   notice: attrd_perform_update: Sent update 14: last-failure-f1-1=1375340845
Aug  1 16:07:25 dev2 attrd[18154]:     info: find_hash_entry: Creating hash entry for fail-count-f1-2
Aug  1 16:07:25 dev2 attrd[18154]:     info: attrd_local_callback: Expanded fail-count-f1-2=value++ to 1
Aug  1 16:07:25 dev2 attrd[18154]:   notice: attrd_trigger_update: Sending flush op to all hosts for: fail-count-f1-2 (1)
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_modify operation for section status: OK (rc=0, origin=local/attrd/14, version=0.8.28)
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_query operation for section //cib/status//node_state[@id='3232261523']//transient_attributes//nvpair[@name='fail-count-f1-2']: No such device or address (rc=-6, origin=local/attrd/15, version=0.8.28)
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_query operation for section /cib: OK (rc=0, origin=local/attrd/16, version=0.8.28)
Aug  1 16:07:25 dev2 attrd[18154]:   notice: attrd_perform_update: Sent update 17: fail-count-f1-2=1
Aug  1 16:07:25 dev2 attrd[18154]:     info: find_hash_entry: Creating hash entry for last-failure-f1-2
Aug  1 16:07:25 dev2 attrd[18154]:   notice: attrd_trigger_update: Sending flush op to all hosts for: last-failure-f1-2 (1375340845)
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_modify operation for section status: OK (rc=0, origin=local/attrd/17, version=0.8.29)
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_query operation for section //cib/status//node_state[@id='3232261523']//transient_attributes//nvpair[@name='last-failure-f1-2']: No such device or address (rc=-6, origin=local/attrd/18, version=0.8.29)
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_query operation for section /cib: OK (rc=0, origin=local/attrd/19, version=0.8.29)
Aug  1 16:07:25 dev2 attrd[18154]:   notice: attrd_perform_update: Sent update 20: last-failure-f1-2=1375340845
Aug  1 16:07:25 dev2 cib[18151]:     info: cib_process_request: Completed cib_modify operation for section status: OK (rc=0, origin=local/attrd/20, version=0.8.30)
Aug  1 16:07:25 dev2 stonith-ng[18398]:   notice: crm_add_logfile: Additional logging available in /var/log/ha-debug
Aug  1 16:07:25 dev2 stonith-ng[18398]:    debug: crm_update_callsites: Enabling callsites based on priority=7, files=(null), functions=(null), formats=(null), tags=(null)
Aug  1 16:07:25 dev2 stonith-ng[18398]:     info: crm_log_init: Changed active directory to /var/lib/heartbeat/cores/root
```

If this commit is applied, PGID will become like below.

```
UID        PID  PPID  PGID   SID  C STIME TTY          TIME CMD
root     28347     1 28347 28347  2 17:33 ?        00:00:01 corosync
root     28353     1 28353 28353  0 17:33 ?        00:00:00 /usr/sbin/pacemakerd -f
root     28356 28353 28356 28356  0 17:33 ?        00:00:00 /usr/libexec/pacemaker/stonithd
root     28357 28353 28357 28357  0 17:33 ?        00:00:00 /usr/libexec/pacemaker/lrmd
root     28585 28356 28585 28356  1 17:34 ?        00:00:00 /usr/bin/perl /usr/sbin/fence_legacy
root     28586 28585 28585 28356  0 17:34 ?        00:00:00 stonith -t external/libvirt.NG1 -E -T reset dev1
root     28591 28586 28585 28356  0 17:34 ?        00:00:00 /bin/sh /usr/lib64/stonith/plugins/external/libvirt.NG1 reset dev1
root     28595 28591 28585 28356  0 17:34 ?        00:00:00 sleep 135
991      28355 28353 28355 28355  0 17:33 ?        00:00:00 /usr/libexec/pacemaker/cib
991      28358 28353 28358 28358  0 17:33 ?        00:00:00 /usr/libexec/pacemaker/attrd
991      28359 28353 28359 28359  0 17:33 ?        00:00:00 /usr/libexec/pacemaker/pengine
991      28360 28353 28360 28360  0 17:33 ?        00:00:00 /usr/libexec/pacemaker/crmd
```