fix(query): set correct tsrow index.

source/dnode/vnode/src/tsdb/tsdbRead.c

@@ -3373,13 +3373,13 @@ int32_t doMergeMemTableMultiRows(TSDBROW* pRow, uint64_t uid, SIterInfo* pIter,
     } else {  // has next point in mem/imem
       pNextRow = getValidMemRow(pIter, pDelList, pReader);
       if (pNextRow == NULL) {
-        *pResRow = *pRow;
+        *pResRow = current;
         *freeTSRow = false;
         return TSDB_CODE_SUCCESS;
       }
 
       if (TSDBROW_TS(&current) != TSDBROW_TS(pNextRow)) {
-        *pResRow = *pRow;
+        *pResRow = current;
         *freeTSRow = false;
         return TSDB_CODE_SUCCESS;
       }