Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3, the linked list should become 1 -> 2 -> 4 after calling your function.
这道题有一个限制条件就是产出的这个节点不是最后一个结点，如果要删除最后一个节点不能通过这种方法。

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
void deleteNode(struct ListNode* node) 
{
    struct ListNode *nextnode = node->next;
    node->val = nextnode->val;
    node->next = nextnode->next;
    free(nextnode);
    
}