Retrying failed requests when draining would make the draining hung. So it
is better not to trigger the retry timer when draining. And after the
virtual devices go back to work, they would retry those queued requests.
Signed-off-by: Jiahui Cen <cenjiahui@huawei.com>
Signed-off-by: Ying Fang <fangying1@huawei.com>
