blk-throttle: fix typo in comment of throtl_adjusted_limit

lapsed time -> elapsed time

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Kemeng Shi <shikemeng@huawei.com>
Link: https://lore.kernel.org/r/20221205115709.251489-7-shikemeng@huaweicloud.com


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