Motor OS: fix compile error

PR rust-lang#146341 introduced
a compilation error. This fixes it.

Author: lasiotus

library/std/src/sys/fs/motor.rs

@@ -4,7 +4,7 @@ use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, SeekFrom};
 use crate::os::fd::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, RawFd};
 use crate::path::{Path, PathBuf};
 use crate::sys::fd::FileDesc;
-pub use crate::sys::fs::common::exists;
+pub use crate::sys::fs::common::{Dir, exists};
 use crate::sys::time::SystemTime;
 use crate::sys::{AsInner, AsInnerMut, FromInner, IntoInner, map_motor_error, unsupported};