allow oom_adj of saintly processes

If the badness of a process is zero then oom_adj>0 has no effect.  This
patch makes sure that the oom_adj shift actually increases badness points
appropriately.

Signed-off-by: Joshua N. Pritikin <jpritikin@pobox.com>
Cc: Andrea Arcangeli <andrea@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/oom_kill.c

@@ -147,9 +147,11 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 	 * Adjust the score by oomkilladj.
 	 */
 	if (p->oomkilladj) {
-		if (p->oomkilladj > 0)
+		if (p->oomkilladj > 0) {
+			if (!points)
+				points = 1;
 			points <<= p->oomkilladj;
-		else
+		} else
 			points >>= -(p->oomkilladj);
 	}