fix

Signed-off-by: qupeng <qupeng@pingcap.com>

cdc/processor/sinkmanager/table_sink_worker.go

@@ -199,14 +199,11 @@ func (w *sinkWorker) handleTask(ctx context.Context, task *sinkTask) (finalErr e
 		failpoint.Inject("TableSinkWorkerFetchFromCache", func() {
 			err = tablesink.NewSinkInternalError(errors.New("TableSinkWorkerFetchFromCacheInjected"))
 		})
-		if err != nil {
-			return errors.Trace(err)
-		}
-		// We have drained all events from the cache, we can return directly.
-		// No need to get events from the source manager again.
-		if drained {
-			performCallback(lowerBound.Prev())
-			return nil
+		performCallback(lowerBound.Prev())
+		if err != nil || drained {
+			// If drained is true it means we have drained all events from the cache,
+			// we can return directly instead of get events from the source manager again.
+			return err
 		}
 	}