update header files to 3.6
diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index 0aa3805..1ef80ef 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -84,6 +84,8 @@
 	__u32	bitmap;
 };
 
+#define XFRMA_REPLAY_ESN_MAX	4096
+
 struct xfrm_replay_state_esn {
 	unsigned int	bmp_len;
 	__u32		oseq;