How do I add user2 into user1's friend list?
/*
 * Make two users friends with each other.  This is symmetric - a pointer to
 * each user must be stored in the 'friends' array of the other.
 *
 * New friends must be added in the first empty spot in the 'friends' array.
 *
 * Return:
 *   - 0 on success.
 *   - 1 if the two users are already friends.
 *   - 2 if the users are not already friends, but at least one already has
 *     MAX_FRIENDS friends.
 *   - 3 if the same user is passed in twice.
 *   - 4 if at least one user does not exist.
 *
 * Do not modify either user if the result is a failure.
 * NOTE: If multiple errors apply, return the *largest* error code that applies.
 */
int make_friends(const char *name1, const char *name2, User *head) {
    //User *user1 = malloc(sizeof(User));
    //User *user2 = malloc(sizeof(User));
    //strcpy(user1->name, name1);
    //strcpy(user2->name, name2);
    //struct user friends_list1[MAX_FRIENDS];
    //struct user friends_list2[MAX_FRIENDS];
    User *user1 = find_user(name1, head);
    User *user2 = find_user(name2, head);
    User *friends_list1 = user1->friends[MAX_FRIENDS];
    User *friends_list2 = user2->friends[MAX_FRIENDS];

    //friends_list1 = user1->friends[MAX_FRIENDS];
    //friends_list2 = user2->friends[MAX_FRIENDS];
    //user1->friends[MAX_FRIENDS] = *friends_list1;
    //user2->friends[MAX_FRIENDS] = *friends_list2;

    if (user1 == user2) {
        return 3;
    }

    if ( user1 == NULL || user2 == NULL) {
        return 4;
    }

    for (int i = 0; i < MAX_FRIENDS; i++) {
        if (strcmp(friends_list1[i].name, user2->name) == 0) {
            return 1;
            break;
        } else {
            curr = head;
            if (curr.next == NULL) {
                strcpy(friends_list1[i].name, user2->name);
                //printf("%p", friends_list1[i]->name);
                break;
            }
        } 
        curr = curr->next;
    }