blk-mq: bitmap tag: fix races on shared ::wake_index fields

Fix racy updates of shared blk_mq_bitmap_tags::wake_index
and blk_mq_hw_ctx::wake_index fields.

Cc: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --cc block/blk-mq-tag.c
Simple merge

diff --cc block/blk-mq-tag.h
Simple merge

diff --cc include/linux/blk-mq.h
Simple merge