Impact: cleanup

make code more readable and more like 64-bit
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <49AE48B4.8010907@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>