audio: fix crate path

src/audio.rs

@@ -2,10 +2,10 @@
 // This file is part of vlc-rs.
 // Licensed under the MIT license, see the LICENSE file.
 
-use sys;
-use ::MediaPlayer;
-use ::TrackDescription;
-use ::tools::from_cstr;
+use crate::sys;
+use crate::MediaPlayer;
+use crate::TrackDescription;
+use crate::tools::from_cstr;
 
 pub trait MediaPlayerAudioEx {
     fn get_mute(&self) -> Option<bool>;