[RTNETLINK]: Fix rtnetlink compat attribute patch

Sent the wrong patch previously.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 6731e7f..c91476c 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -570,12 +570,16 @@
 }
 
 extern int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len);
-extern int rtattr_parse_nested_compat(struct rtattr *tb[], int maxattr,
-				      struct rtattr *rta, void **data, int len);
+extern int __rtattr_parse_nested_compat(struct rtattr *tb[], int maxattr,
+				        struct rtattr *rta, int len);
 
 #define rtattr_parse_nested(tb, max, rta) \
 	rtattr_parse((tb), (max), RTA_DATA((rta)), RTA_PAYLOAD((rta)))
 
+#define rtattr_parse_nested_compat(tb, max, rta, data, len) \
+({	data = RTA_PAYLOAD(rta) >= len ? RTA_DATA(rta) : NULL; \
+	__rtattr_parse_nested_compat(tb, max, rta, len); })
+
 extern int rtnetlink_send(struct sk_buff *skb, u32 pid, u32 group, int echo);
 extern int rtnl_unicast(struct sk_buff *skb, u32 pid);
 extern int rtnl_notify(struct sk_buff *skb, u32 pid, u32 group,