Update to kernel headers v4.12.3.

Test: Built angler.
Change-Id: Icbcf4fac2334de8409b049ed7a3b4c24b4e98ce9
diff --git a/libc/kernel/uapi/linux/seg6_hmac.h b/libc/kernel/uapi/linux/seg6_hmac.h
index 14a838b..d5ef671 100644
--- a/libc/kernel/uapi/linux/seg6_hmac.h
+++ b/libc/kernel/uapi/linux/seg6_hmac.h
@@ -18,6 +18,7 @@
  ****************************************************************************/
 #ifndef _UAPI_LINUX_SEG6_HMAC_H
 #define _UAPI_LINUX_SEG6_HMAC_H
+#include <linux/types.h>
 #include <linux/seg6.h>
 #define SEG6_HMAC_SECRET_LEN 64
 #define SEG6_HMAC_FIELD_LEN 32