tests: move makeInterest/makeData/etc to ndn::tests namespace

refs #2376

Change-Id: If824388f1e2859d7d2199cd622db2aa1a3277798
diff --git a/tests/unit-tests/management/nfd-controller.t.cpp b/tests/unit-tests/management/nfd-controller.t.cpp
index 1beb5db..bc9aa1a 100644
--- a/tests/unit-tests/management/nfd-controller.t.cpp
+++ b/tests/unit-tests/management/nfd-controller.t.cpp
@@ -31,8 +31,7 @@
 namespace nfd {
 namespace tests {
 
-using ndn::util::makeData;
-using ndn::util::makeNack;
+using namespace ndn::tests;
 
 BOOST_AUTO_TEST_SUITE(Management)