vhost/net: fix rcu check usage

Incorrect rcu check was used as rcu isn't done
under mutex here. Force check to 1 for now,
to stop it from complaining.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vhost/net.c

@@ -129,8 +129,9 @@ static void handle_tx(struct vhost_net *net)
 	size_t hdr_size;
 	struct socket *sock;
 
-	sock = rcu_dereference_check(vq->private_data,
-				     lockdep_is_held(&vq->mutex));
+	/* TODO: check that we are running from vhost_worker?
+	 * Not sure it's worth it, it's straight-forward enough. */
+	sock = rcu_dereference_check(vq->private_data, 1);
 	if (!sock)
 		return;