dev: update __dev_notify_flags() to send rtnl msg

This patch only prepares the next one, there is no functional change.
Now, __dev_notify_flags() can also be used to notify flags changes via
rtnetlink.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 25ab6fe..594a6b0 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5235,10 +5235,14 @@
 	return ret;
 }
 
-void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
+void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
+			unsigned int gchanges)
 {
 	unsigned int changes = dev->flags ^ old_flags;
 
+	if (gchanges)
+		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges);
+
 	if (changes & IFF_UP) {
 		if (dev->flags & IFF_UP)
 			call_netdevice_notifiers(NETDEV_UP, dev);
@@ -5274,10 +5278,7 @@
 		return ret;
 
 	changes = old_flags ^ dev->flags;
-	if (changes)
-		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
-
-	__dev_notify_flags(dev, old_flags);
+	__dev_notify_flags(dev, old_flags, changes);
 	return ret;
 }
 EXPORT_SYMBOL(dev_change_flags);