fw: FaceTable iterator dereferences to Face& instead of shared_ptr

This commit also improves the speed and reliability of
Mgmt/TestFaceManager/CreateFace test suite.

refs #3205

Change-Id: Idd013488ced2d7f8072ef8a3d910f94da2e0c8ac
diff --git a/daemon/mgmt/face-manager.hpp b/daemon/mgmt/face-manager.hpp
index b97a629..aa0c05d 100644
--- a/daemon/mgmt/face-manager.hpp
+++ b/daemon/mgmt/face-manager.hpp
@@ -105,7 +105,7 @@
 
 private: // helpers for StatusDataset handler
   bool
-  doesMatchFilter(const ndn::nfd::FaceQueryFilter& filter, shared_ptr<Face> face);
+  matchFilter(const ndn::nfd::FaceQueryFilter& filter, const Face& face);
 
   /** \brief get status of face, including properties and counters
    */