Fix clippy::redundant_field_names

examples/transcode-audio.rs

@@ -116,9 +116,9 @@ fn transcoder<P: AsRef<Path>>(
 
     Ok(Transcoder {
         stream: input.index(),
-        filter: filter,
-        decoder: decoder,
-        encoder: encoder,
+        filter,
+        decoder,
+        encoder,
     })
 }