staging: android/lowmemorykiller: Do not kill kernel threads

LMK should not try killing kernel threads.
Suggested-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/lowmemorykiller.c

@@ -138,6 +138,9 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
 		struct task_struct *p;
 		int oom_adj;
 
+		if (tsk->flags & PF_KTHREAD)
+			continue;
+
 		p = find_lock_task_mm(tsk);
 		if (!p)
 			continue;