If pci_register_driver() fails we're incorrectly unregistering the root
device with device_unregister() rather than root_device_unregister().
Reported-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>