Removing hack for stopping libvirt-guests as conflict service

Due to recent fix in libvirt, libvirt-guests daemon now returns right
error code when checking its status. Thanks to that we can treat
libvirt-guests as all other daemons.

Change-Id: I61b274587e811edfbe63a02d762764700acd3eec
Signed-off-by: Yaniv Bronhaim <ybronhei@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/21205
Reviewed-by: Dan Kenigsberg <danken@redhat.com>