Phonet: handle rtnetlink registration failure

Signed-off-by: RĂ©mi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/phonet/pn_dev.h b/include/net/phonet/pn_dev.h
index 59ae628..4ba2aed 100644
--- a/include/net/phonet/pn_dev.h
+++ b/include/net/phonet/pn_dev.h
@@ -38,7 +38,7 @@
 
 int phonet_device_init(void);
 void phonet_device_exit(void);
-void phonet_netlink_register(void);
+int phonet_netlink_register(void);
 struct net_device *phonet_device_get(struct net *net);
 
 int phonet_address_add(struct net_device *dev, u8 addr);