gluster/CLI: crash upon executing "peer status" command

Problem:
While doing "gluster peer status", cli_cmd_peer_status_cbk() creates
the frame and passes as arg to gf_cli_list_friends() which sets
frame->local to GF_CLI_LIST_PEERS flag (value: 0x1). It expects
gf_cli_list_friends_cbk() [invoked through cli_cmd_submit()] to
reset frame->local to NULL. But if cli_cmd_submit() fails some
where before gf_cli_list_friends_cbk() gets invoked, then the
flag value remains in frame->local and causes a SEGV while
destroying the stack i.e. [CLI_STACK_DESTROY => cli_local_wipe()].

Fix:
In gf_cli_list_friends(), if cli_cmd_submit() fails, then
reset the value of frame->local to NULL.

Change-Id: Ied19f07eaf67e3bd42c75cdc2ff3729b0789e632
BUG: 961691
Signed-off-by: Santosh Kumar Pradhan <spradhan@redhat.com>
Reviewed-on: http://review.gluster.org/4976
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>