mgmt: FaceManager no longer owns FaceSystem

refs #3904

Change-Id: I2ef6fd36a51493eea27d8eb0e1c7dc022766f948
diff --git a/daemon/mgmt/face-manager.cpp b/daemon/mgmt/face-manager.cpp
index a2bfc3c..4d1929d 100644
--- a/daemon/mgmt/face-manager.cpp
+++ b/daemon/mgmt/face-manager.cpp
@@ -35,10 +35,11 @@
 
 NFD_LOG_INIT("FaceManager");
 
-FaceManager::FaceManager(FaceTable& faceTable, Dispatcher& dispatcher, CommandAuthenticator& authenticator)
+FaceManager::FaceManager(FaceSystem& faceSystem,
+                         Dispatcher& dispatcher, CommandAuthenticator& authenticator)
   : NfdManagerBase(dispatcher, authenticator, "faces")
-  , m_faceSystem(faceTable)
-  , m_faceTable(faceTable)
+  , m_faceSystem(faceSystem)
+  , m_faceTable(faceSystem.getFaceTable())
 {
   registerCommandHandler<ndn::nfd::FaceCreateCommand>("create",
     bind(&FaceManager::createFace, this, _2, _3, _4, _5));