message: Fix fseeko not flushing write buffer
diff: @@ -484,6 +484,11 @@ pub unsafe extern "C" fn fseeko(stream: *mut FILE, mut off: off_t, whence: c_int
  off -= (stream.read_size - stream.read_pos) as off_t;
  }
  + // Flush write buffer before seek
  + if stream.flush().is_err() {
  + return -1;
  + }
  +
  let err = Sys::lseek(*stream.file, off, whence);
  if err < 0 {
  return err as c_int;
  