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/virtio_blk.h b/libc/kernel/uapi/linux/virtio_blk.h
index 9dc7aa7..48abcff 100644
--- a/libc/kernel/uapi/linux/virtio_blk.h
+++ b/libc/kernel/uapi/linux/virtio_blk.h
@@ -36,9 +36,9 @@
 #define VIRTIO_BLK_F_BARRIER 0
 #define VIRTIO_BLK_F_SCSI 7
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define VIRTIO_BLK_F_WCE 9
+#define VIRTIO_BLK_F_FLUSH 9
 #define VIRTIO_BLK_F_CONFIG_WCE 11
-#define VIRTIO_BLK_F_FLUSH VIRTIO_BLK_F_WCE
+#define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH
 #endif
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define VIRTIO_BLK_ID_BYTES 20