mgmt: simplify StatusDataset implementation

Change-Id: Icf21cfd8bc47333461dadd06c347b723e77f5784
diff --git a/tests/unit/mgmt/nfd/controller.t.cpp b/tests/unit/mgmt/nfd/controller.t.cpp
index f7f4a9a..d68611f 100644
--- a/tests/unit/mgmt/nfd/controller.t.cpp
+++ b/tests/unit/mgmt/nfd/controller.t.cpp
@@ -47,7 +47,7 @@
   }
 
 protected:
-  Controller::CommandSuccessCallback succeedCallback = [this] (const auto& params) {
+  CommandSuccessCallback succeedCallback = [this] (const auto& params) {
     succeeds.push_back(params);
   };
   std::vector<ControlParameters> succeeds;