ipv6: notify userspace when we added or changed an ipv6 token

NetworkManager might want to know that it changed when the router advertisement
arrives.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/addrconf.c

@@ -4531,6 +4531,7 @@ static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token)
 	}
 
 	write_unlock_bh(&idev->lock);
+	inet6_ifinfo_notify(RTM_NEWLINK, idev);
 	addrconf_verify_rtnl();
 	return 0;
 }