Pass shutoff reason to release hook

Pass shutoff reason to release hook

Sometimes in release hook it is useful to know if the VM shutdown was graceful
or not. This is especially useful to do cleanup based on the VM shutdown failure
reason in release hook. This patch proposes to use the last argument 'extra'
to pass VM shutoff reason in the call to release hook.
Making this change for Qemu and LXC.

Signed-off-by: Swapnil Ingle <swapnil.ingle@nutanix.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>