Clean up trailing whitespace in the kernel headers.

And fix the scripts so they stop letting trailing whitespace through.

Change-Id: Ie109fbe1f63321e565ba0fa60fee8e9cf3a61cfc
diff --git a/libc/kernel/common/linux/percpu.h b/libc/kernel/common/linux/percpu.h
index 9597e29..92c0b6e 100644
--- a/libc/kernel/common/linux/percpu.h
+++ b/libc/kernel/common/linux/percpu.h
@@ -18,11 +18,11 @@
  ****************************************************************************/
 #ifndef __LINUX_PERCPU_H
 #define __LINUX_PERCPU_H
-#include <linux/spinlock.h>  
-#include <linux/slab.h>  
+#include <linux/spinlock.h>
+#include <linux/slab.h>
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #include <linux/smp.h>
-#include <linux/string.h>  
+#include <linux/string.h>
 #include <asm/percpu.h>
 #ifndef PERCPU_ENOUGH_ROOM
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */