Comment remaining non-cross-signing-compliant components

Fixes https://github.com/vector-im/riot-web/issues/11748

src/components/views/elements/DeviceVerifyButtons.js

@@ -22,6 +22,8 @@ import sdk from '../../../index';
 import Modal from '../../../Modal';
 import { _t } from '../../../languageHandler';
 
+// XXX: This component is *not* cross-signing aware. Once everything is
+// cross-signing, this component should just go away.
 export default createReactClass({
     displayName: 'DeviceVerifyButtons',
 

src/components/views/rooms/MemberDeviceInfo.js

@@ -23,6 +23,8 @@ import classNames from 'classnames';
 export default class MemberDeviceInfo extends React.Component {
     render() {
         const DeviceVerifyButtons = sdk.getComponent('elements.DeviceVerifyButtons');
+        // XXX: These checks are not cross-signing aware but this component is only used
+        // from the old, pre-cross-signing memberinfopanel
         const iconClasses = classNames({
             mx_MemberDeviceInfo_icon: true,
             mx_MemberDeviceInfo_icon_blacklisted: this.props.device.isBlocked(),