tests+tools: minor code cleanup

Change-Id: Ic3356d4a18a8e5eeb45fc076fc0563c3d1549c8a
diff --git a/tests/tools/ndn-autoconfig/multicast-discovery.t.cpp b/tests/tools/ndn-autoconfig/multicast-discovery.t.cpp
index 0e08a36..62d8bf1 100644
--- a/tests/tools/ndn-autoconfig/multicast-discovery.t.cpp
+++ b/tests/tools/ndn-autoconfig/multicast-discovery.t.cpp
@@ -124,7 +124,7 @@
   });
 
   stage.start();
-  face.processEvents(time::seconds(20));
+  face.processEvents(20_s);
   BOOST_CHECK(hasSuccess);
 }