net: remove _readableState from debug statement

Ref: #445
PR-URL: #45063
Refs: #445
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Minwoo Jung <nodecorelab@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/net.js

@@ -496,8 +496,7 @@ Socket.prototype._final = function(cb) {
 function afterShutdown() {
   const self = this.handle[owner_symbol];
 
-  debug('afterShutdown destroyed=%j', self.destroyed,
-        self._readableState);
+  debug('afterShutdown destroyed=%j', self.destroyed);
 
   this.callback();
 }