Revert "blk-mq: fix null pointer dereference in blk_mq_queue_tag_busy_ite"

hulk inclusion
category: bugfix
bugzilla: 187497, https://gitee.com/openeuler/kernel/issues/I5MT95


CVE: NA

--------------------------------

This reverts commit 64ba823f.

Commit fea9f92f introduce the bug. It is a patch for performance
optimization and this version doesn't have to backport it.
blk_mq_queue_tag_busy_iter() won't access q->tag_set->flags or reference
other fields in q that is uninitialized at present. 64ba823f will
make io hang for special scsi drivers(e.x. ata_piix). Revert it.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>