message: Use relibc chdir for fchdir
diff: @@ -232,7 +232,7 @@ impl Pal for Sys {
  !0
  } else {
  match str::from_utf8(&buf[..res]) {
  - Ok(path) => e(syscall::chdir(&path)) as c_int,
  + Ok(path) => Sys::chdir(&CString::new(path).unwrap()),
  Err(_) => {
  unsafe { errno = EINVAL };
  return -1;
  