blk-mq: Drop 'reserved' arg of busy_tag_iter_fn

blk-mq: Drop 'reserved' arg of busy_tag_iter_fn

We no longer use the 'reserved' arg in busy_tag_iter_fn for any iter
function so it may be dropped.

Signed-off-by: John Garry <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Reviewed-by: Sagi Grimberg <[email protected]> #nvme
Reviewed-by: Bart Van Assche <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>