reset the guest vring avail/used idx fields, otherwise it's possible
that old values remain in memory which would cause a reboot to fail
with a "Guest moved used index" message
Signed-off-by: NJens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>