test: refactor test-beforeexit-event-exit.js

PR-URL: nodejs#10577
Reviewed-By: Italo A. Casas <me@italoacasas.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-beforeexit-event-exit.js

@@ -1,9 +1,8 @@
 'use strict';
-require('../common');
-const assert = require('assert');
+const common = require('../common');
 
 process.on('beforeExit', function() {
-  assert(false, 'exit should not allow this to occur');
+  common.fail('exit should not allow this to occur');
 });
 
 process.exit();