[C] List Reverse

listReverse.c

int listReverse(struct ListNode** head) {
    int node_count = 0;
    struct ListNode *tmp = NULL, *walker = *head;
    
    if (walker != NULL) {
        node_count = 1;
        while (walker->next != NULL) {
            tmp = walker->next;
            walker->next = tmp->next;
            tmp->next = *head;
            *head = tmp;
            node_count++;
        }
    }
    
    return node_count;
}