Update to v6.0 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-6.0

Test: Boots on coral.
Test: Bionic unit tests pass.
Change-Id: I282de83f23b432bef58214108a93700bdadddf0f
diff --git a/libc/kernel/uapi/linux/rtnetlink.h b/libc/kernel/uapi/linux/rtnetlink.h
index 321e487..7201827 100644
--- a/libc/kernel/uapi/linux/rtnetlink.h
+++ b/libc/kernel/uapi/linux/rtnetlink.h
@@ -323,7 +323,7 @@
 #define RTNH_DATA(rtnh) ((struct rtattr *) (((char *) (rtnh)) + RTNH_LENGTH(0)))
 struct rtvia {
   __kernel_sa_family_t rtvia_family;
-  __u8 rtvia_addr[0];
+  __u8 rtvia_addr[];
 };
 struct rta_cacheinfo {
   __u32 rta_clntref;