xfrm: handle NETDEV_UNREGISTER for xfrm device

This patch to handle the asynchronous unregister
device event so the device IPsec offload resources
could be cleanly released.

Fixes: e4db5b6 ("xfrm: policy: remove pcpu policy cache")
Signed-off-by: Raed Salem <[email protected]>
Reviewed-by: Boris Pismenny <[email protected]>
Reviewed-by: Saeed Mahameed <[email protected]>
Signed-off-by: Steffen Klassert <[email protected]>

Author: Raed Salem

net/xfrm/xfrm_device.c

@@ -383,6 +383,7 @@ static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void
 		return xfrm_dev_feat_change(dev);
 
 	case NETDEV_DOWN:
+	case NETDEV_UNREGISTER:
 		return xfrm_dev_down(dev);
 	}
 	return NOTIFY_DONE;