USB: legousbtower: zero driver data at allocation

{

	struct device *idev = &interface->dev;

	struct usb_device *udev = interface_to_usbdev(interface);

	struct lego_usb_tower *dev = NULL;

	struct lego_usb_tower *dev;

	struct tower_get_version_reply *get_version_reply = NULL;

	int retval = -ENOMEM;

	int result;

	/* allocate memory for our device state and initialize it */

	dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);

	if (!dev)

		goto exit;

	mutex_init(&dev->lock);

	dev->udev = usb_get_dev(udev);

	dev->open_count = 0;

	dev->disconnected = 0;

	dev->read_buffer = NULL;

	dev->read_buffer_length = 0;

	dev->read_packet_length = 0;

	spin_lock_init (&dev->read_buffer_lock);

	dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout);

	dev->read_last_arrival = jiffies;

	init_waitqueue_head (&dev->read_wait);

	init_waitqueue_head (&dev->write_wait);

	dev->interrupt_in_buffer = NULL;

	dev->interrupt_in_endpoint = NULL;

	dev->interrupt_in_urb = NULL;

	dev->interrupt_in_running = 0;

	dev->interrupt_in_done = 0;

	dev->interrupt_out_buffer = NULL;

	dev->interrupt_out_endpoint = NULL;

	dev->interrupt_out_urb = NULL;

	dev->interrupt_out_busy = 0;

	result = usb_find_common_endpoints_reverse(interface->cur_altsetting,

			NULL, NULL,

			&dev->interrupt_in_endpoint,