[PATCH v4.19.y 0/2] Please backport de53fd7aedb1 : sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices

Here's the backported patches for 4.19.y. Logic is basically the same, the issue was primarily with patch context. The patches are really back-ports and not cherry-picks because of that, if that's an issue feel free to change the text description.

[PATCH v4.19.y 1/2] sched/fair: Fix low cpu usage with high throttling by [PATCH v4.19.y 2/2] sched/fair: Fix -Wunused-but-set-variable warnings