Avoid deprecated ndn-cxx functions

Change-Id: Ib9220786a724327b89dcc328c8f34a5c8fe1fdd9
diff --git a/tests/unit/mgmt/management-tool.t.cpp b/tests/unit/mgmt/management-tool.t.cpp
index db2eaa0..97282d1 100644
--- a/tests/unit/mgmt/management-tool.t.cpp
+++ b/tests/unit/mgmt/management-tool.t.cpp
@@ -201,7 +201,6 @@
       }
     }
     NDN_THROW(Error("Certificate not found in keyChain"));
-    return rtn;
   }
 
   Certificate
@@ -1038,7 +1037,7 @@
   using security::transform::streamSink;
   using security::transform::bufferSource;
 
-  bufferSource(rrset1.getData().wire(), rrset1.getData().size()) >> base64Encode() >> streamSink(os);
+  bufferSource(rrset1.getData()) >> base64Encode() >> streamSink(os);
 
   std::string expectedValue = os.str();