block: remove "select BLK_RQ_IO_DATA_LEN" from BLK_CGROUP_IOCOST dependency

The configuration item BLK_RQ_IO_DATA_LEN is not declared in the kernel.
Select BLK_RQ_IO_DATA_LEN is meaningless which could be removed.

Signed-off-by: Ying Sun <sunying@nj.iscas.ac.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220629062409.19458-1-sunying@nj.iscas.ac.cn


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