The exact, general goal of the function bfq_split_bfqq() is not that
apparent. Add a comment to make it clear.
Tested-by: NOleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>