blk-mq: use queue_hctx in blk_mq_map_queue_type

blk-mq: use queue_hctx in blk_mq_map_queue_type

Some caller of blk_mq_map_queue_type now didn't grab
'q_usage_counter', such as blk_mq_cpu_mapped_to_hctx, so we need
protect 'queue_hw_ctx' through rcu.

Also checked all other functions, no more missed cases.

Fixes: 89e1fb7ceffd ("blk-mq: fix potential uaf for 'queue_hw_ctx'")
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>