To reduce some duplicated code, factor out blkcg_iostat_update(). No
functional change.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220629070917.3113016-2-yanaijie@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>