Finetune Rust code.

codes/rust/chapter_stack_and_queue/array_deque.rs

@@ -116,6 +116,7 @@ impl ArrayDeque {
     }
 }
 
+/* Driver Code */
 fn main() {
     /* 初始化双向队列 */
     let mut deque = ArrayDeque::new(10);

codes/rust/chapter_stack_and_queue/array_queue.rs

@@ -82,6 +82,7 @@ impl ArrayQueue {
     }
 }
 
+/* Driver Code */
 fn main() {
     /* 初始化队列 */
     let capacity = 10;