misc: remove recoveryCallback from watchCmd

Trying to kill an old process on recovery became obsolete since the
introduction of deathSignal. Even more, considering that the recovery
may happen on a different host, killProcRollback had a really little
chance to succeed.

Change-Id: I9ebbcdb10882ac031712d107485560883c4720a9
Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/26872
Reviewed-by: Saggi Mizrahi <smizrahi@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>