crypto: hisilicon/qm - stop qp by judging sq and cq tail

It is not working well to determine whether the queue is empty based on
whether the used count is 0. It is more stable to get if the queue is
stopping by checking if the tail pointer of the send queue and the
completion queue are equal.

Signed-off-by: Yang Shen <shenyang39@huawei.com>
Signed-off-by: Shukun Tan <tanshukun1@huawei.com>
Reviewed-by: Zhou Wang <wangzhou1@hisilicon.com>
Reviewed-by: Zaibo Xu <xuzaibo@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>