nd_device_unregister
nd_device_unregister(dev, ND_SYNC);
EXPORT_SYMBOL(nd_device_unregister);
nd_device_unregister(dev, ND_ASYNC);
nd_device_unregister(dev, ND_SYNC);
nd_device_unregister(dev, ND_ASYNC);
void nd_device_unregister(struct device *dev, enum nd_async_mode mode);
nd_device_unregister(dev, ND_SYNC);
nd_device_unregister(&nd_region->dev, ND_SYNC);