message: Use constant from result
diff: @@ -6,13 +6,13 @@ use crate::futures;
  use crate::result::OtherError;
  use crate::result::TockError;
  use crate::result::TockResult;
  +use crate::result::EALREADY;
  use crate::syscalls;
  use core::cell::Cell;
  use core::isize;
  use core::ops::{Add, AddAssign, Sub};
  const DRIVER_NUMBER: usize = 0x00000;
  -const EALREADY: isize = -3;
  mod command_nr {
  pub const IS_DRIVER_AVAILABLE: usize = 0;
  