virtio_net: Use virtio_find_vqs_ctx() helper

virtio_find_vqs_ctx() is defined but never be called currently,
it is the right place to use it.
Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/virtio_net.c

@@ -2847,7 +2847,7 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
 			ctx[rxq2vq(i)] = true;
 	}
 
-	ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
+	ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
 				  names, ctx, NULL);
 	if (ret)
 		goto err_find;