Clippy: Resolve derivable-impls

src/scheduler/task.rs

@@ -221,6 +221,7 @@ impl TaskHandlePriorityQueue {
 	}
 }
 
+#[derive(Default)]
 struct QueueHead {
 	head: Option<Rc<RefCell<Task>>>,
 	tail: Option<Rc<RefCell<Task>>>,
@@ -235,15 +236,6 @@ impl QueueHead {
 	}
 }
 
-impl Default for QueueHead {
-	fn default() -> Self {
-		Self {
-			head: None,
-			tail: None,
-		}
-	}
-}
-
 /// Realize a priority queue for tasks
 pub struct PriorityTaskQueue {
 	queues: [QueueHead; NO_PRIORITIES],