Clear the list of search results displayed in tag assignments when no…

… results are returned.

x-pack/plugins/beats_management/public/pages/main/tags.tsx

@@ -155,7 +155,7 @@ export class TagsPage extends React.PureComponent<TagsPageProps, TagsPageState>
           this.setState({
             assignmentOptions: {
               ...this.state.assignmentOptions,
-              searchFailureMessage: 'Beat not found.',
+              searchResults: [],
             },
           });
           this.notifyBeatNotFound(beatId);