net: switchdev: recurse into __switchdev_handle_fdb_del_to_device

The difference between __switchdev_handle_fdb_del_to_device and
switchdev_handle_del_to_device is that the former takes an extra
orig_dev argument, while the latter starts with dev == orig_dev.

We should recurse into the variant that does not lose the orig_dev along
the way. This is relevant when deleting FDB entries pointing towards a
bridge (dev changes to the lower interfaces, but orig_dev shouldn't).

The addition helper already recurses properly, just the deletion one
doesn't.

Fixes: 8ca07176 ("net: switchdev: introduce a fanout helper for SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>