nfp_fl_lag_changels_event() never fails, and therefore we would
never return NOTIFY_BAD for NETDEV_CHANGELOWERSTATE.  Make this
clearer by changing nfp_fl_lag_changels_event()'s return type
to void.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NJohn Hurley <john.hurley@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>