mlxsw: spectrum_switchdev: Schedule respin during trans prepare

Since there's no special support for the bridge events, the driver
returns -EOPNOTSUPP, and thus the commit never happens. Therefore
schedule respin during the prepare stage: there's no real difference one
way or another.

This fixes the problem that mirror-to-gretap offload wouldn't adapt to
changes in bridge vlan configuration right away and another notification
would have to arrive for mlxsw to catch up.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

@@ -1697,7 +1697,7 @@ static int mlxsw_sp_port_obj_add(struct net_device *dev,
 		vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);
 		err = mlxsw_sp_port_vlans_add(mlxsw_sp_port, vlan, trans);
 
-		if (switchdev_trans_ph_commit(trans)) {
+		if (switchdev_trans_ph_prepare(trans)) {
 			/* The event is emitted before the changes are actually
 			 * applied to the bridge. Therefore schedule the respin
 			 * call for later, so that the respin logic sees the