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/tcp-factory.hpp b/daemon/face/tcp-factory.hpp
index 519d2dc..212acbb 100644
--- a/daemon/face/tcp-factory.hpp
+++ b/daemon/face/tcp-factory.hpp
@@ -34,7 +34,7 @@
 
 /** \brief Protocol factory for TCP over IPv4 and IPv6
  */
-class TcpFactory : public ProtocolFactory
+class TcpFactory final : public ProtocolFactory
 {
 public:
   static const std::string&
@@ -61,15 +61,15 @@
    */
   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;
 
   ndn::nfd::FaceScope
   determineFaceScopeFromAddresses(const boost::asio::ip::address& local,