Fix delta calculations for cases where a scaling factor has been defined

tools/dcdbquery/query.cpp

@@ -170,8 +170,8 @@ void DCDBQuery::genOutput(std::list<DCDB::SensorDataStoreReading> &results, quer
 		std::cout << ",";
 	    }
 	}
-	prevValue = (*reading).value;
-	prevT = (*reading).timeStamp.getRaw();
+	prevValue = value;
+	prevT = ts;
 	std::cout << std::endl;
     }
 }