face: remove nfd::ProtocolFactory type alias

Change-Id: Iac0af82a5301245e621a39f3bfc98aaed8dbaa45
diff --git a/daemon/face/protocol-factory.hpp b/daemon/face/protocol-factory.hpp
index 4535d3f..b8bba3d 100644
--- a/daemon/face/protocol-factory.hpp
+++ b/daemon/face/protocol-factory.hpp
@@ -28,6 +28,7 @@
 
 #include "channel.hpp"
 #include "face-system.hpp"
+
 #include <ndn-cxx/encoding/nfd-constants.hpp>
 #include <boost/range/adaptor/map.hpp>
 #include <boost/range/algorithm/copy.hpp>
@@ -159,9 +160,6 @@
 };
 
 } // namespace face
-
-using face::ProtocolFactory;
-
 } // namespace nfd
 
 /** \brief registers a protocol factory
diff --git a/daemon/mgmt/face-manager.cpp b/daemon/mgmt/face-manager.cpp
index 4cc3288..eeea696 100644
--- a/daemon/mgmt/face-manager.cpp
+++ b/daemon/mgmt/face-manager.cpp
@@ -108,7 +108,7 @@
     }
   }
 
-  ProtocolFactory* factory = m_faceSystem.getFactoryByScheme(remoteUri.getScheme());
+  face::ProtocolFactory* factory = m_faceSystem.getFactoryByScheme(remoteUri.getScheme());
   if (factory == nullptr) {
     NFD_LOG_TRACE("received create request for unsupported protocol: " << remoteUri.getScheme());
     done(ControlResponse(406, "Unsupported protocol"));
@@ -299,8 +299,8 @@
 FaceManager::listChannels(const Name& topPrefix, const Interest& interest,
                           ndn::mgmt::StatusDatasetContext& context)
 {
-  std::set<const ProtocolFactory*> factories = m_faceSystem.listProtocolFactories();
-  for (const ProtocolFactory* factory : factories) {
+  std::set<const face::ProtocolFactory*> factories = m_faceSystem.listProtocolFactories();
+  for (const auto* factory : factories) {
     for (const auto& channel : factory->getChannels()) {
       ndn::nfd::ChannelStatus entry;
       entry.setLocalUri(channel->getUri().toString());
diff --git a/tests/daemon/mgmt/face-manager.t.cpp b/tests/daemon/mgmt/face-manager.t.cpp
index c953d3b..8856b0a 100644
--- a/tests/daemon/mgmt/face-manager.t.cpp
+++ b/tests/daemon/mgmt/face-manager.t.cpp
@@ -249,7 +249,7 @@
   }
 };
 
-class TestProtocolFactory : public ProtocolFactory
+class TestProtocolFactory : public face::ProtocolFactory
 {
 public:
   void