Clippy code cleanup

src/data_provider/history.rs

@@ -70,7 +70,7 @@ pub fn push_note(set_id: u32, item: HistoryItem) {
         item.before,
         item.after
     );
-    writeln!(&mut file, "{}", line_str.to_string()).unwrap();
+    writeln!(&mut file, "{}", line_str).unwrap();
 }
 
 pub fn history_dir() -> PathBuf {