qm: fix the way judge whether q stop in user space

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

In this patch, we try to fix the way judge whether q stop in user
space.
The driver judge whether device stop by parameter qp_status.used,
but this parameter only used in kernel. So we compare sqc and cqc
tail to judge finish status of tasks for user space.

Signed-off-by: Yu'an Wang <wangyuan46@huawei.com>
Reviewed-by: Cheng Hu <hucheng.hu@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>