fixup! events: add hasEventListener util for validate

Author: chosunghoon

lib/events.js

@@ -673,7 +673,7 @@ EventEmitter.prototype.prependOnceListener =
 EventEmitter.prototype.removeListener =
     function removeListener(type, listener) {
       checkListener(listener);
-      
+
       if (!hasEventListener(this, type))
         return this;
 
@@ -781,7 +781,7 @@ EventEmitter.prototype.removeAllListeners =
 function _listeners(target, type, unwrap) {
   if (!hasEventListener(target, type))
     return [];
-  
+
   const evlistener = target._events[type];
 
   if (typeof evlistener === 'function')