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/btrfs_tree.h b/libc/kernel/uapi/linux/btrfs_tree.h
index 02a9ae4..3becce8 100644
--- a/libc/kernel/uapi/linux/btrfs_tree.h
+++ b/libc/kernel/uapi/linux/btrfs_tree.h
@@ -221,7 +221,7 @@
   __le64 parent_objectid;
   __le64 index;
   __le16 name_len;
-  __u8 name[0];
+  __u8 name[];
 } __attribute__((__packed__));
 struct btrfs_timespec {
   __le64 sec;