xennet_tx_bug_gc can free the skb before we use it, so make sure we don't.
Signed-off-by: NKeir Fraser <keir@xensource.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>