face: avoid multiple onFail events

refs #1497

Change-Id: I8fda3fea5cd8a314b30eef45da104109e9748afc
diff --git a/daemon/face/websocket-face.cpp b/daemon/face/websocket-face.cpp
index 5dfe516..9e56bb5 100644
--- a/daemon/face/websocket-face.cpp
+++ b/daemon/face/websocket-face.cpp
@@ -1,12 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014  Regents of the University of California,
- *                     Arizona Board of Regents,
- *                     Colorado State University,
- *                     University Pierre & Marie Curie, Sorbonne University,
- *                     Washington University in St. Louis,
- *                     Beijing Institute of Technology,
- *                     The University of Memphis
+ * Copyright (c) 2014,  Regents of the University of California,
+ *                      Arizona Board of Regents,
+ *                      Colorado State University,
+ *                      University Pierre & Marie Curie, Sorbonne University,
+ *                      Washington University in St. Louis,
+ *                      Beijing Institute of Technology,
+ *                      The University of Memphis
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
@@ -65,7 +65,7 @@
       websocketpp::lib::error_code ecode;
       m_server.close(m_handle, websocketpp::close::status::normal, "closed by nfd", ecode);
 
-      onFail("Face closed");
+      fail("Face closed");
     }
 }