Revert "sched/psi: Rearrange polling code in preparation"

This reverts commit c176dda0 which is
commit 7fab21fa upstream.

It is part of a patch series that breaks the Android API.  If this
series is needed in Android devices in the future, it can come back in
an ABI-safe manner.

Bug: 161946584
Change-Id: I086b52b9a332fac76c3b96c71d7bba9eeeabb9e8
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>