关于while(L)的错误问题（需要运行调试！）

#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
#define OVERFLOW 0
#define OK 1
#define ERROR 0
typedef int Status;
typedef int ElemType;
typedef struct LNode
{
    ElemType data;
    struct LNode *next;
}LNode;//定义结构体

void mune();
int ClearList_L(LNode *L);
Status InitList_L(LNode *L);
Status CreateList_L(LNode *L,int n);//声明函数

Status InitList_L(LNode *L)
{
    L=(LNode*)malloc(sizeof(LNode));
    if(!L) return OVERFLOW;
    L->next=NULL;
    return OK;
}//初始化
Status CreateList_L(LNode *L,int n)
{
    LNode *p;
    int i;
    if(!L) return ERROR;
    if(L->next) ClearList_L(L);
    for(i=n;i>0;--i)
    {
        p=(LNode*)malloc(sizeof(LNode));
        printf("第%d个结点的数据为：\n",i);
        scanf(" %d",&(p->data));
        p->next=L->next;
        L->next=p;
    }
}
//创建
//遍历
//读取第i个元素
//插入
//删除
//求长度
int ClearList_L(LNode *L)
{
    LNode *LNext;
    while(L==NULL)
    {
        printf("链表为空！");
        return 0;
    }
    while((L->next)!=NULL)
    {
        LNext=L->next;
        free(L);
        L=LNext;
        printf("已清空！");
    }
    return 0;
}//清空
//销毁
void mune()
{
    printf("请输入您选择的操作：\nr.创建\nt.遍历\ng.读取指定元素\ni.插入\nd.删除\nl.求长度\nc.清空\nx.退出程序\n");
}
//目录
int main()
{
    int n;
    char opp;
    LNode *L;
    if(!InitList_L(L)) printf("初始化失败！\n");
        else printf("初始化成功！\n");
    while(1)
    {
        mune();
        scanf(" %c",&opp);
        switch(opp)
        {
            case 'r':
                {
                    printf("请输入创建结点个数：\n");
                    scanf(" %d",&n);
                    CreateList_L(L,n);
                    break;
                }
            case 't':break;
            case 'g':break;
            case 'i':break;
            case 'd':break;
            case 'l':break;
            case 'c':ClearList_L(L);break;
            case 'x':break;
            default: printf("请重新输入！\n");
        }
    }
}