fix emberrasing mistake

Author: benjamingr

lib/fs.js

@@ -1848,7 +1848,7 @@ ReadStream.prototype.destroy = function() {
 ReadStream.prototype.close = function(cb) {
 
   const close = (fd) => {
-    fs.close(fd || this.fd, function(er) {
+    fs.close(fd || this.fd, (er) => {
       if (er)
         this.emit('error', er);
       else