Avoid using deprecated ndn-cxx type aliases

Change-Id: I55fd500377698adc8035113bdff2d64091a36e07
diff --git a/tests/route/test-name-prefix-table.cpp b/tests/route/test-name-prefix-table.cpp
index 9c9833f..1425603 100644
--- a/tests/route/test-name-prefix-table.cpp
+++ b/tests/route/test-name-prefix-table.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  The University of Memphis,
+ * Copyright (c) 2014-2023,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -315,7 +315,7 @@
 
 BOOST_FIXTURE_TEST_CASE(UpdateFromLsdb, NamePrefixTableFixture)
 {
-  ndn::time::system_clock::TimePoint testTimePoint =  ndn::time::system_clock::now();
+  auto testTimePoint = ndn::time::system_clock::now();
   NamePrefixList npl1;
   ndn::Name n1("name1");
   ndn::Name n2("name2");