Update to kernel headers v4.9.3.

Test: Built arm, arm64, x86, x86_64 targets.
Test: Booted on angler, and ran bionic unit tests (32 bit and 64 bit).

Change-Id: I14a8dcbea11b41f83431eabed6590cd25af07b1d
diff --git a/libc/kernel/uapi/linux/if_bridge.h b/libc/kernel/uapi/linux/if_bridge.h
index 2ef8f28..1b7aa47 100644
--- a/libc/kernel/uapi/linux/if_bridge.h
+++ b/libc/kernel/uapi/linux/if_bridge.h
@@ -151,7 +151,7 @@
   __u64 tx_packets;
   __u16 vid;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-  __u16 pad1;
+  __u16 flags;
   __u32 pad2;
 };
 enum {