Revert "sched/fair: Detect capacity inversion"

This reverts commit 99b704ae.

It breaks the Android kernel abi, so revert it.  If it needs to come
back later, it can do so in an abi-safe way.

Bug: 161946584
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I98d18871912e9ad4c178cf0661a5973137f6dc83