core: ignore non-Ethernet AF_LINK addresses when enumerating NICs.

Also modernize the code with some C++11 features.

Change-Id: Ibd29b39c37fdce8f87f917ab0cf48750e631e76c
diff --git a/daemon/face/ethernet-factory.hpp b/daemon/face/ethernet-factory.hpp
index f7f6588..b7d5ec0 100644
--- a/daemon/face/ethernet-factory.hpp
+++ b/daemon/face/ethernet-factory.hpp
@@ -72,7 +72,7 @@
    * \throws EthernetFactory::Error or EthernetFace::Error
    */
   shared_ptr<EthernetFace>
-  createMulticastFace(const shared_ptr<NetworkInterfaceInfo>& interface,
+  createMulticastFace(const NetworkInterfaceInfo& interface,
                       const ethernet::Address& address);
 
   /**