Revert "sched: Fix DEBUG && !SCHEDSTATS warn"

This reverts commit 0a008c50 which is
commit 769fdf83 upstream.

It needs to be reverted as a later change to be reverted depends on this
fixup being gone.  If it is needed in the future it can come back in an
abi-safe way.

Bug: 161946584
Change-Id: I4effa5266207c9499867d16f3248732e0f6bc526
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>