[media] radio-si470x: fix memory leak in si470x_usb_driver_probe()

radio->int_in_urb is not deallocated on error paths in si470x_usb_driver_probe().

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/radio/si470x/radio-si470x-usb.c

@@ -699,7 +699,7 @@ static int si470x_usb_driver_probe(struct usb_interface *intf,
 	radio->videodev = video_device_alloc();
 	if (!radio->videodev) {
 		retval = -ENOMEM;
-		goto err_intbuffer;
+		goto err_urb;
 	}
 	memcpy(radio->videodev, &si470x_viddev_template,
 			sizeof(si470x_viddev_template));
@@ -790,6 +790,8 @@ static int si470x_usb_driver_probe(struct usb_interface *intf,
 	kfree(radio->buffer);
 err_video:
 	video_device_release(radio->videodev);
+err_urb:
+	usb_free_urb(radio->int_in_urb);
 err_intbuffer:
 	kfree(radio->int_in_buffer);
 err_radio: