FIXUP: sched: scheduler-driven cpu frequency selection

Two fixups that have been reported on LKML. The next version of
scheduler-driver cpu frequency selection patch set should include
these fixes and we can drop this patch then.

Signed-off-by: Ricky Liang <jcliang@chromium.org>

Change-Id: Ia2f8b5c0dd5dac06580256eeb4b259929688af68