core: unlock_entity script should validate...

unlock_entity script should validate command line before asking confirmation

Change-Id: I1c7011b97e6796e096a8985180138d6ae7447270
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=974924
Signed-off-by: Eli Mesika <emesika@redhat.com>