virtio_net: ensure netdev_tx_reset_queue is called on bind xsk for tx

virtnet_sq_bind_xsk_pool() flushes tx skbs and then resets tx queue, so
DQL counters need to be reset when flushing has actually occurred, Add
virtnet_sq_free_unused_buf_done() as a callback for virtqueue_resize()
to handle this.

Fixes: 21a4e3c ("virtio_net: xsk: bind/unbind xsk for tx")
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/virtio_net.c

@@ -5740,7 +5740,8 @@ static int virtnet_sq_bind_xsk_pool(struct virtnet_info *vi,
 
 	virtnet_tx_pause(vi, sq);
 
-	err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf, NULL);
+	err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf,
+			      virtnet_sq_free_unused_buf_done);
 	if (err) {
 		netdev_err(vi->dev, "reset tx fail: tx queue index: %d err: %d\n", qindex, err);
 		pool = NULL;