clean code with clippy

src/model/tripdetails.rs

@@ -120,9 +120,9 @@ ORDER BY day;",
 
     pub(crate) async fn user_allowed_to_change(&self, db: &SqlitePool, user: &User) -> bool {
         if self.belongs_to_event(db).await {
-            return user.is_admin;
+            user.is_admin
         } else {
-            return self.user_is_cox(db, user).await != CoxAtTrip::No;
+            self.user_is_cox(db, user).await != CoxAtTrip::No
         }
     }