[libvirt] [PATCH]: Fix non-live migration failure

There is a logic error in the Qemu driver when doing a non-live migrate. During a non-live migrate, on the source host during the Perform step, we pause the domain; however, if there was ever a failure, we were forgetting to unpause the domain, meaning that the domain was paused forever. Add a flag to tell us when we should unpause the domain after a failure. Also, as pointed out by DV, we were unnecessarily using a snprintf to a buffer to execute qemu monitor commands, when we could get away with just sending a static string. Fix that as well. Signed-off-by: Chris Lalancette <clalance(a)redhat.com&gt;