Revert "sched: Change nr_uninterruptible type to unsigned long"

This reverts commit 9ef510db which is
commit 36569780 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ifac0b7b03da2a3ff5b9f1e95865e12ca7747d7c8
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>