Fix not emit removeListener  when type of eventName is 'symbol'

```js
const EventEmitter = require('events');
const myEmitter = new EventEmitter();
const sym = Symbol('symbol');
const fn = () => { };
myEmitter.on(sym, fn);

myEmitter.on('removeListener', (...args) => {
  console.log('removeListener');
  console.log(args, args[0] === sym, args[1] === fn);
});

myEmitter.removeAllListeners()
```