tests+tools: minor code cleanup

Change-Id: Ic3356d4a18a8e5eeb45fc076fc0563c3d1549c8a
diff --git a/tools/nfdc/execute-command.cpp b/tools/nfdc/execute-command.cpp
index 92f1631..7067ebf 100644
--- a/tools/nfdc/execute-command.cpp
+++ b/tools/nfdc/execute-command.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2014-2017,  Regents of the University of California,
+/*
+ * Copyright (c) 2014-2019,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -32,7 +32,7 @@
 time::nanoseconds
 ExecuteContext::getTimeout() const
 {
-  return time::seconds(4);
+  return 4_s;
 }
 
 ndn::nfd::CommandOptions