message: Have `open()` and `dup()` match `-1` for `Err` instead of `0`
diff: @@ -6,14 +6,14 @@ pub struct RawFile(usize);
  impl RawFile {
  pub fn open<T: AsRef<[u8]>>(path: T, flags: usize, mode: usize) -> Result<RawFile, ()> {
  match open(path.as_ref()[0] as *const i8, flags as i32, mode as u16) {
  - 0 => Err(()),
  + -1 => Err(()),
  n => Ok(RawFile(n as usize))
  }
  }
  pub fn dup(&self, _buf: &[u8]) -> Result<RawFile, ()> {
  match dup(self.0 as i32) {
  - 0 => Err(()),
  + -1 => Err(()),
  n => Ok(RawFile(n as usize))
  }
  }
  