blk-mq: support batched queue_rqs() on shared tags queue

Since active requests have been accounted when allocate driver tags,
we can remove this limit now.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230913151616.3164338-4-chengming.zhou@linux.dev


Signed-off-by: Jens Axboe <axboe@kernel.dk>