Update 0707.设计链表.md

结构体语法有错，中间有个free少了分号

problems/0707.设计链表.md

@@ -157,7 +157,7 @@ private:
 ## 其他语言版本
 C:
 ```C
-typedef struct {
+typedef struct MyLinkedList {
     int val;
     struct MyLinkedList* next;
 }MyLinkedList;
@@ -233,7 +233,7 @@ void myLinkedListDeleteAtIndex(MyLinkedList* obj, int index) {
         MyLinkedList *tmp = obj->next;
         if (tmp != NULL){
             obj->next = tmp->next;
-            free(tmp)     
+            free(tmp);
         }
         return;
     }
@@ -263,20 +263,21 @@ void myLinkedListFree(MyLinkedList* obj) {
 }
 
 /**
+
  * Your MyLinkedList struct will be instantiated and called as such:
  * MyLinkedList* obj = myLinkedListCreate();
  * int param_1 = myLinkedListGet(obj, index);
- 
+
  * myLinkedListAddAtHead(obj, val);
- 
+
  * myLinkedListAddAtTail(obj, val);
- 
+
  * myLinkedListAddAtIndex(obj, index, val);
- 
+
  * myLinkedListDeleteAtIndex(obj, index);
- 
+
  * myLinkedListFree(obj);
-*/
+ */
 ```
 
 Java：