clean code with clippy

src/model/rower.rs

@@ -39,7 +39,7 @@ WHERE id in (SELECT rower_id FROM rower WHERE logbook_id=?)
         )
         .execute(db)
         .await
-        .map_err(|e| return e.to_string())?;
+        .map_err(|e| e.to_string())?;
 
         Ok(())
     }