Revert "sched: re-calculate a cpu's next_balance point upon sched domain changes"

This reverts commit f420356120c207e3852207e4e70b2621a3eeeebe.
Revert "sched: Make sure to not re-read variables after validation"

This reverts commit 3609201f5409940a01e4e765bb50d5d0ecf5dbb7.