Update function return types

src/ol/control/Control.js

@@ -12,7 +12,7 @@ import {removeNode} from '../dom.js';
  * @property {HTMLElement} [element] The element is the control's
  * container element. This only needs to be specified if you're developing
  * a custom control.
- * @property {function(import("../MapEvent.js").default)} [render] Function called when
+ * @property {function(import("../MapEvent.js").default):void} [render] Function called when
  * the control should be re-rendered. This is called in a `requestAnimationFrame`
  * callback.
  * @property {HTMLElement|string} [target] Specify a target if you want