USB: fix usbled disconnect read race #2

usbled has a race where show methods for attributes in sysfs can
follow a NULL pointer during disconnect. The correct ordering fixes
it.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/misc/usbled.c

@@ -144,12 +144,14 @@ static void led_disconnect(struct usb_interface *interface)
 	struct usb_led *dev;
 
 	dev = usb_get_intfdata (interface);
-	usb_set_intfdata (interface, NULL);
 
 	device_remove_file(&interface->dev, &dev_attr_blue);
 	device_remove_file(&interface->dev, &dev_attr_red);
 	device_remove_file(&interface->dev, &dev_attr_green);
 
+	/* first remove the files, then set the pointer to NULL */
+	usb_set_intfdata (interface, NULL);
+
 	usb_put_dev(dev->udev);
 
 	kfree(dev);