media: usb: dvb-usb-v2: zd1301: fix missing platform_device_unregister()

Add the missing platform_device_unregister() before return
from zd1301_frontend_attach in the error handling case when
pdev->dev.driver is empty.

There's an error handling route named err_platform_device_unregister,
so just reuse it.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/usb/dvb-usb-v2/zd1301.c

@@ -150,7 +150,7 @@ static int zd1301_frontend_attach(struct dvb_usb_adapter *adap)
 	}
 	if (!pdev->dev.driver) {
 		ret = -ENODEV;
-		goto err;
+		goto err_platform_device_unregister;
 	}
 	if (!try_module_get(pdev->dev.driver->owner)) {
 		ret = -ENODEV;