The RPC console is closed when the libvirt-sandbox-init-common
binary reports the exit of the guest process. We still have
some cleanup code that runs in the guest, for example, syncing
and ummounting filesystems. We want to be able to see debug
and/or error messages from this code, so we should not quit
until we get a close on that console. This should happen a
few ms after the close on the RPC console, but just in case
something causes shutdown to hang, we have a delayed timer
registered.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>