Merge pull request #7669 from taosdata/hotfix/TD-6426

[td-6426]fix subquery no result issue

src/client/src/tscSubquery.c

@@ -3411,6 +3411,7 @@ static void doBuildResFromSubqueries(SSqlObj* pSql) {
   }
 
   if (numOfRes == 0) {  // no result any more, free all subquery objects
+    pSql->res.completed = true;
     freeJoinSubqueryObj(pSql);
     return;
   }