Revert "sched: Change nr_uninterruptible type to unsigned long"

This reverts commit 7c2a7b77 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: I1296de71adc9e60db7b1d66c08e069b8d40c68d6
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>