virtqueue_kick() falls back to returning true

[Snild Dolkow <snild@xxxxxxxx>]

If virtqueue_prepare() fails, virtqueue_kick() falls back to returning true:

	/**
	 * virtqueue_kick - update after add_buf
	 * @vq: the struct virtqueue
	 *
	 * After one or more virtqueue_add_* calls, invoke this to kick
	 * the other side.
	 *
	 * Caller must ensure we don't call this with other virtqueue
	 * operations at the same time (except where noted).
	 *
	 * Returns false if kick failed, otherwise true.
	 */
	bool virtqueue_kick(struct virtqueue *vq)
	{
		if (virtqueue_kick_prepare(vq))
			return virtqueue_notify(vq);
		return true;
	}