fix(graph): no symbol when offset is not defined

This may be a bug raised from #14375

src/chart/helper/Line.ts

@@ -70,7 +70,7 @@ function createSymbol(name: 'fromSymbol' | 'toSymbol', lineData: LineList, idx:
 
     const symbolSize = lineData.getItemVisual(idx, name + 'Size' as 'fromSymbolSize' | 'toSymbolSize');
     const symbolRotate = lineData.getItemVisual(idx, name + 'Rotate' as 'fromSymbolRotate' | 'toSymbolRotate');
-    const symbolOffset = lineData.getItemVisual(idx, name + 'Offset' as 'fromSymbolOffset' | 'toSymbolOffset');
+    const symbolOffset = lineData.getItemVisual(idx, name + 'Offset' as 'fromSymbolOffset' | 'toSymbolOffset') || 0;
     const symbolKeepAspect = lineData.getItemVisual(idx,
         name + 'KeepAspect' as 'fromSymbolKeepAspect' | 'toSymbolKeepAspect');