xfrm: align nlattr properly when needed

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index 2cd9e60..1433389 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -302,6 +302,7 @@
 	XFRMA_SA_EXTRA_FLAGS,	/* __u32 */
 	XFRMA_PROTO,		/* __u8 */
 	XFRMA_ADDRESS_FILTER,	/* struct xfrm_address_filter */
+	XFRMA_PAD,
 	__XFRMA_MAX
 
 #define XFRMA_MAX (__XFRMA_MAX - 1)