blk-iocost: Factor out the base vrate change into a separate function

Factor out the base vrate change code into a separate function
to fimplify the ioc_timer_fn().

No functional change.

Signed-off-by: Baolin Wang <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
1 file changed