'bfqq->bfqd' is ensured to set in bfq_init_queue(), and it will never
change afterwards.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220816015631.1323948-3-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>