blk-mq-debugfs: Show active requests per queue for shared tags

blk-mq-debugfs: Show active requests per queue for shared tags

Currently we show the hctx.active value for the per-hctx "active" file.

However this is not maintained for shared tags, and we instead keep a
record of the number active requests per request queue - see commit
f1b49fdc1c64 ("blk-mq: Record active_queues_shared_sbitmap per tag_set for
when using shared sbitmap).

Change for the case of shared tags to show the active requests per request
queue by using __blk_mq_active_requests() helper.

Signed-off-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1635496823-33515-1-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>