core: unlock_entity should unlock unattached disks
core: unlock_entity should unlock unattached disks

unlock_entity.sh script does not unlock locked images that are not
attached to any VM.

The script should unlock any disks, even such that were created and are
not attached to a VM.

Change-Id: I8346f0ae34a7b2ea9d4ce4281dbebdb67a554ac0
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1032910
Signed-off-by: Eli Mesika <dc8a2a200abf66067593de2e51fee9376f06ea0f@redhat.com>

walteryang47/ovirt-engine,walteryang47/ovirt-engine,OpenUniversity/ovirt-engine,walteryang47/ovirt-engine,yingyun001/ovirt-engine,OpenUniversity/ovirt-engine,zerodengxinchao/ovirt-engine,zerodengxinchao/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,yingyun001/ovirt-engine,eayun/ovirt-engine,eayun/ovirt-engine,yapengsong/ovirt-engine,eayun/ovirt-engine,eayun/ovirt-engine,yapengsong/ovirt-engine,walteryang47/ovirt-engine,OpenUniversity/ovirt-engine,yapengsong/ovirt-engine,halober/ovirt-engine,halober/ovirt-engine,eayun/ovirt-engine,OpenUniversity/ovirt-engine,yapengsong/ovirt-engine,yingyun001/ovirt-engine,zerodengxinchao/ovirt-engine,yingyun001/ovirt-engine,halober/ovirt-engine,halober/ovirt-engine,yingyun001/ovirt-engine,walteryang47/ovirt-engine,yapengsong/ovirt-engine,zerodengxinchao/ovirt-engine