Function mutex_unlock

user/src/sync.rs:12–14

(mutex_id: usize)

    sys_mutex_lock(mutex_id);
}
pub fn mutex_unlock(mutex_id: usize) {
    sys_mutex_unlock(mutex_id);
}
pub fn semaphore_create(res_count: usize) -> isize {
    sys_semaphore_create(res_count)
}