Update to v4.15 kernel headers.

Test: Compiles, boots bullhead/hikey960.
Change-Id: I118beb8b6cac0881b1270f9bf6981959297a41a8
diff --git a/libc/kernel/uapi/linux/rtnetlink.h b/libc/kernel/uapi/linux/rtnetlink.h
index c363e34..80ba16e 100644
--- a/libc/kernel/uapi/linux/rtnetlink.h
+++ b/libc/kernel/uapi/linux/rtnetlink.h
@@ -318,6 +318,8 @@
 #define RTAX_QUICKACK RTAX_QUICKACK
   RTAX_CC_ALGO,
 #define RTAX_CC_ALGO RTAX_CC_ALGO
+  RTAX_FASTOPEN_NO_COOKIE,
+#define RTAX_FASTOPEN_NO_COOKIE RTAX_FASTOPEN_NO_COOKIE
   __RTAX_MAX
 };
 #define RTAX_MAX (__RTAX_MAX - 1)
@@ -402,6 +404,7 @@
   TCA_PAD,
   TCA_DUMP_INVISIBLE,
   TCA_CHAIN,
+  TCA_HW_OFFLOAD,
   __TCA_MAX
 };
 #define TCA_MAX (__TCA_MAX - 1)