Revert "sched/nohz: Fix rq->cpu_load[] calculations"

This reverts commit 6162a4ea112fd80e117016cf5b051467830b362e.
Revert "sched/nohz: Rewrite and fix load-avg computation -- again"

This reverts commit d8fa00df38b0ff7ad27fc511faa705603b42a1e9.