Update to kernel headers v4.7.2.

Modify the kernel header update script to rename C++ keyword
struct members to something else. This fixes problems when including
these kernel files in C++ code.

Also, make a manual change to linux/fib_rules.h and comment out the
value FRA_PAD since it conflicts with a special android kernel value
FRA_UID_START that has not been upstreamed yet.

Test: Built aosp_angler, aosp_x86_64, aosp_mips (bionic only)
Test: Booted on angler and ran bionic unit tests
Test: Built these changes in internal master

Change-Id: Ia22b7e3ca409404696dba76311f49157f4a9ceed
diff --git a/libc/kernel/uapi/linux/raid/md_u.h b/libc/kernel/uapi/linux/raid/md_u.h
index 66ab2ba..7556eee 100644
--- a/libc/kernel/uapi/linux/raid/md_u.h
+++ b/libc/kernel/uapi/linux/raid/md_u.h
@@ -62,7 +62,7 @@
   int minor_version;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
   int patch_version;
-  int ctime;
+  unsigned int ctime;
   int level;
   int size;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
@@ -71,7 +71,7 @@
   int md_minor;
   int not_persistent;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-  int utime;
+  unsigned int utime;
   int state;
   int active_disks;
   int working_disks;