face: allow the creation of permanent TCP faces

Change-Id: I516c176b000a78012f2ef7bd7f1f3e74c1758a94
Refs: #3167
diff --git a/tests/other/face-benchmark.cpp b/tests/other/face-benchmark.cpp
index 36bc4f4..289a270 100644
--- a/tests/other/face-benchmark.cpp
+++ b/tests/other/face-benchmark.cpp
@@ -128,6 +128,7 @@
     auto port = boost::lexical_cast<uint16_t>(uriR.getPort());
     if (uriR.getScheme() == "tcp4") {
       m_tcpChannel.connect(tcp::Endpoint(addr, port),
+                           ndn::nfd::FACE_PERSISTENCY_PERSISTENT,
                            false,
                            bind(&FaceBenchmark::onRightFaceCreated, this, faceL, _1),
                            bind(&FaceBenchmark::onFaceCreationFailed, _1, _2));