drivers: usb: smsusb: fix error handling code in smsusb_init_device

The previous commit 4b208f8b ("[media] siano: register media controller
earlier")moves siano_media_device_register before smscore_register_device,
and adds corresponding error handling code if smscore_register_device
fails. However, it misses the following error handling code of
smsusb_init_device.

Fix this by moving error handling code at the end of smsusb_init_device
and adding a goto statement in the following error handling parts.

Fixes: 4b208f8b

 ("[media] siano: register media controller earlier")
Signed-off-by: Dongliang Mu <dzm91@hust.edu.cn>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>