virtio_net: fix a typo in virtnet_alloc_queues()

Obviously it should check !vi->rq.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/virtio_net.c

@@ -1347,7 +1347,7 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
 	if (!vi->sq)
 		goto err_sq;
 	vi->rq = kzalloc(sizeof(*vi->rq) * vi->max_queue_pairs, GFP_KERNEL);
-	if (!vi->sq)
+	if (!vi->rq)
 		goto err_rq;
 
 	INIT_DELAYED_WORK(&vi->refill, refill_work);