static void flush_bufs(struct virtqueue *vq, bool can_sleep)
{
	struct port_buffer *buf;
	unsigned int len;

	while ((buf = virtqueue_get_buf(vq, &len)))
		free_buf(buf, can_sleep);
}
static void flush_bufs(struct virtqueue *vq, bool can_sleep)
{
	struct port_buffer *buf;
	unsigned int len;

	while ((buf = virtqueue_get_buf(vq, &len)))
		free_buf(buf, can_sleep);
}