nvme: wait until quiesce is done

nvme: wait until quiesce is done

NVMe uses one atomic flag to check if quiesce is needed. If quiesce is
started, the helper returns immediately. This way is wrong, since we
have to wait until quiesce is done.

Fixes: e70feb8b3e68 ("blk-mq: support concurrent queue quiesce/unquiesce")
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20211109071144.181581-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>