cargo fmt rust code (#1131)

* cargo fmt code

* Add empty line to seperate unrelated comments

* Fix review

* Update bubble_sort.rs

* Update merge_sort.rs

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/rust/chapter_stack_and_queue/queue.rs

@@ -38,4 +38,4 @@ pub fn main() {
     // 判断队列是否为空
     let is_empty = queue.is_empty();
     print!("\n队列是否为空 = {is_empty}");
-}
+}