Merge pull request #2064 from taosdata/hotfix/subinsert

[td-409]fix bug that callback function is not set correctly in sub-in…

src/client/src/tscSubquery.c

@@ -1764,6 +1764,11 @@ int32_t tscHandleMultivnodeInsert(SSqlObj *pSql) {
       break;
     }
   
+    /*
+     * assign the callback function to fetchFp to make sure that the error process function can restore
+     * the callback function (multiVnodeInsertMerge) correctly.
+     */
+    pNew->fetchFp = pNew->fp;
     pSql->pSubs[i] = pNew;
     tscTrace("%p sub:%p create subObj success. orderOfSub:%d", pSql, pNew, i);
   }