media: cpia2_usb: drop bogus interface-release call

Drop bogus call to usb_driver_release_interface() from the disconnect()
callback. As the interface is already being unbound at this point,
usb_driver_release_interface() simply returns early.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>