Modify the same problem as the return value variable

 Description
     Another two methods in LinkedList and vector have the same return
     value variables, which leads to an error in XTS compilation. You
     can solve this problem by changing it into different variables
     #I4XD1Q:Modify the same problem as the return value variable
Signed-off-by: Nwangyong1995626wywz <wangyong237@huawei.com>

zh-cn/application-dev/reference/apis/js-apis-linkedlist.md

@@ -68,7 +68,7 @@ add(element: T): boolean
 ```
 let linkedList = new LinkedList();
 let result = linkedList.add("a");
-let result = linkedList.add(1);
+let result1 = linkedList.add(1);
 let b = [1, 2, 3];
 linkedList.add(b);
 let c = {name : "lala", age : "13"};

zh-cn/application-dev/reference/apis/js-apis-vector.md

@@ -114,8 +114,8 @@ has(element: T): boolean
 let vector = new Vector();
 let result = vector.has("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
 vector.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
-let result = vector.has("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
-```
+let result1 = vector.has("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+``` 
 
 ### getIndexOf