[TD-2227]<fix>: remove false error message in the log file while no results...

[TD-2227]<fix>: remove false error message in the log file while no results returned from server in case of query against super table.

src/client/src/tscLocalMerge.c

@@ -198,6 +198,7 @@ void tscCreateLocalReducer(tExtMemBuffer **pMemBuffer, int32_t numOfBuffer, tOrd
 
   if (numOfFlush == 0 || numOfBuffer == 0) {
     tscLocalReducerEnvDestroy(pMemBuffer, pDesc, finalmodel, pFFModel, numOfBuffer);
+    pCmd->command = TSDB_SQL_RETRIEVE_EMPTY_RESULT; // no result, set the result empty
     tscDebug("%p retrieved no data", pSql);
     return;
   }