fix none import

Signed-off-by: mujunxiang <1948535941@qq.com>

ecstore/src/utils/os/unix.rs

@@ -1,3 +1,4 @@
+use super::IOStats;
 use crate::{disk::Info, error::Result};
 use nix::sys::{stat::stat, statfs::statfs};
 use std::io::{Error, ErrorKind};

ecstore/src/utils/os/windows.rs

@@ -1,3 +1,4 @@
+use super::IOStats;
 use crate::{disk::Info, error::Result};
 use std::io::{Error, ErrorKind, Result};
 use std::mem;