daemon: mark some classes and methods 'final'

As suggested by gcc's -Wsuggest-final-types and -Wsuggest-final-methods

Change-Id: I1622857ee53581efd0c6ce3fe93199c72202d817
diff --git a/daemon/face/udp-factory.hpp b/daemon/face/udp-factory.hpp
index a0f5b6d..28dbfaa 100644
--- a/daemon/face/udp-factory.hpp
+++ b/daemon/face/udp-factory.hpp
@@ -34,7 +34,7 @@
 
 /** \brief Protocol factory for UDP over IPv4 and IPv6
  */
-class UdpFactory : public ProtocolFactory
+class UdpFactory final : public ProtocolFactory
 {
 public:
   class Error : public ProtocolFactory::Error
@@ -100,15 +100,15 @@
    */
   void
   doProcessConfig(OptionalConfigSection configSection,
-                  FaceSystem::ConfigContext& context) override;
+                  FaceSystem::ConfigContext& context) final;
 
   void
   doCreateFace(const CreateFaceRequest& req,
                const FaceCreatedCallback& onCreated,
-               const FaceCreationFailedCallback& onFailure) override;
+               const FaceCreationFailedCallback& onFailure) final;
 
   std::vector<shared_ptr<const Channel>>
-  doGetChannels() const override;
+  doGetChannels() const final;
 
   /** \brief Create UDP multicast faces on \p netif if needed by \p m_mcastConfig
    *  \return list of faces (just created or already existing) on \p netif