Passing multiple -incoming options used to crash qemu (due to
an invalid state transition incoming->incoming). Instead we now
take the last -incoming option, e.g.:
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>