[RFC PATCH v2 3/3] sched: simplify select_task_rq_fair() with schedule balance map

Since schedule balance map provide the approach to get proper sd directly, simplify the code of select_task_rq_fair() is possible. The new code is designed to reserve most of the old logical, but get rid of those 'for' by using the schedule balance map to locate proper sd directly.

[RFC PATCH v2 3/3] sched: simplify select_task_rq_fair() with schedule balance map

Since schedule balance map provide the approach to get proper sd directly, simplify the code of select_task_rq_fair() is possible. The new code is designed to reserve most of the old logical, but get rid of those 'for' by using the schedule balance map to locate proper sd directly.