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_hashing/simple_hash.rs

@@ -4,7 +4,6 @@
  * Author: night-cruise (2586447362@qq.com)
  */
 
-
 /* 加法哈希 */
 fn add_hash(key: &str) -> i32 {
     let mut hash = 0_i64;
@@ -15,7 +14,7 @@ fn add_hash(key: &str) -> i32 {
     }
 
     hash as i32
-} 
+}
 
 /* 乘法哈希 */
 fn mul_hash(key: &str) -> i32 {
@@ -68,4 +67,4 @@ fn main() {
 
     let hash = rot_hash(key);
     println!("旋转哈希值为 {hash}");
-}
+}