do not override error code when itering ddl rows.

src/storage/ddl/ob_direct_insert_sstable_ctx_new.cpp

@@ -828,8 +828,7 @@ int ObTenantDirectLoadMgr::check_and_process_finished_tablet(
           ret = OB_SUCCESS;
           break;
         } else {
-          // ignore error, iter part row completely.
+          LOG_WARN("iter row failed", K(ret), K(task_id), K(execution_id), K(ls_id), K(tablet_id));
-          ret = OB_SUCCESS;
         }
       }
     }