message: create mutable pointer to reset id
diff: @@ -33,7 +33,7 @@ impl Drop for CondQueue {
  #[no_mangle]
  pub unsafe fn sys_destroy_queue(ptr: usize) -> i32 {
  - let id = ptr as *const usize;
  + let id = ptr as *mut usize;
  if id == ptr::null_mut() {
  debug!("sys_wait: ivalid address to condition variable");
  return -1;
  