transport: use /run/nfd.sock on Linux

refs #5039

Change-Id: Ia81115676427db1ebdf4d72d9aadf2e34e2f0ae6
diff --git a/tests/unit/transport/unix-transport.t.cpp b/tests/unit/transport/unix-transport.t.cpp
index 41c46b9..5711859 100644
--- a/tests/unit/transport/unix-transport.t.cpp
+++ b/tests/unit/transport/unix-transport.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2018 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -32,27 +32,19 @@
 
 using ndn::Transport;
 
-BOOST_AUTO_TEST_CASE(GetDefaultSocketNameOk)
+BOOST_AUTO_TEST_CASE(GetSocketNameFromUri)
 {
   BOOST_CHECK_EQUAL(UnixTransport::getSocketNameFromUri("unix:///tmp/test/nfd.sock"), "/tmp/test/nfd.sock");
-}
-
-BOOST_AUTO_TEST_CASE(GetDefaultSocketNameOkOmittedSocketOmittedProtocol)
-{
+#ifdef __linux__
+  BOOST_CHECK_EQUAL(UnixTransport::getSocketNameFromUri(""), "/run/nfd.sock");
+#else
   BOOST_CHECK_EQUAL(UnixTransport::getSocketNameFromUri(""), "/var/run/nfd.sock");
-}
-
-BOOST_AUTO_TEST_CASE(GetDefaultSocketNameBadWrongTransport)
-{
+#endif // __linux__
   BOOST_CHECK_EXCEPTION(UnixTransport::getSocketNameFromUri("tcp://"),
                         Transport::Error,
                         [] (const Transport::Error& error) {
                           return error.what() == "Cannot create UnixTransport from \"tcp\" URI"s;
                         });
-}
-
-BOOST_AUTO_TEST_CASE(GetDefaultSocketNameBadMalformedUri)
-{
   BOOST_CHECK_EXCEPTION(UnixTransport::getSocketNameFromUri("unix"),
                         Transport::Error,
                         [] (const Transport::Error& error) {