test: add second argument to assert.throws()

The assert.throws() calls in test-event-emitter-max-listeners.js
should include a constructor or RegExp as a second argument.

PR-URL: https://github.com/nodejs/node/pull/9987
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-event-emitter-max-listeners.js

@@ -1,8 +1,8 @@
 'use strict';
 const common = require('../common');
-var assert = require('assert');
-var events = require('events');
-var e = new events.EventEmitter();
+const assert = require('assert');
+const events = require('events');
+const e = new events.EventEmitter();
 
 e.on('maxListeners', common.mustCall(function() {}));
 
@@ -11,14 +11,14 @@ e.setMaxListeners(42);
 
 assert.throws(function() {
   e.setMaxListeners(NaN);
-});
+}, /^TypeError: n must be a positive number$/);
 
 assert.throws(function() {
   e.setMaxListeners(-1);
-});
+}, /^TypeError: n must be a positive number$/);
 
 assert.throws(function() {
   e.setMaxListeners('and even this');
-});
+}, /^TypeError: n must be a positive number$/);
 
 e.emit('maxListeners');