events: setMaxListeners() should not have side effects

This object initialization has been unnecessary since 12cf730b.

Ref #3803.

lib/events.js

@@ -41,7 +41,6 @@ exports.EventEmitter = EventEmitter;
 // that to be increased. Set to zero for unlimited.
 var defaultMaxListeners = 10;
 EventEmitter.prototype.setMaxListeners = function(n) {
-  if (!this._events) this._events = {};
   this._maxListeners = n;
 };
 

test/simple/test-event-emitter-set-max-listeners-side-effects.js

@@ -0,0 +1,30 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var common = require('../common');
+var assert = require('assert');
+var events = require('events');
+
+var e = new events.EventEmitter;
+
+assert.equal(typeof e._events, 'undefined');
+e.setMaxListeners(5);
+assert.equal(typeof e._events, 'undefined');