Update 0019.删除链表的倒数第N个节点.md

更正代码错误

problems/0019.删除链表的倒数第N个节点.md

@@ -82,7 +82,7 @@ public:
         
         // ListNode *tmp = slow->next;  C++释放内存的逻辑
         // slow->next = tmp->next;
-        // delete nth;
+        // delete tmp;
         
         return dummyHead->next;
     }