net: dsa: make port_bridge_leave return void

netdev_upper_dev_unlink() which notifies NETDEV_CHANGEUPPER, returns
void, as well as del_nbp(). So there's no advantage to catch an eventual
error from the port_bridge_leave routine at the DSA level.

Make this routine void for the DSA layer and its existing drivers.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
index 4bcc9eb..95944d5 100644
--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -516,7 +516,7 @@
 	return 0;
 }
 
-static int bcm_sf2_sw_br_leave(struct dsa_switch *ds, int port)
+static void bcm_sf2_sw_br_leave(struct dsa_switch *ds, int port)
 {
 	struct bcm_sf2_priv *priv = ds_to_priv(ds);
 	struct net_device *bridge = priv->port_sts[port].bridge_dev;
@@ -543,8 +543,6 @@
 	core_writel(priv, p_ctl, CORE_PORT_VLAN_CTL_PORT(port));
 	priv->port_sts[port].vlan_ctl_mask = p_ctl;
 	priv->port_sts[port].bridge_dev = NULL;
-
-	return 0;
 }
 
 static int bcm_sf2_sw_br_set_stp_state(struct dsa_switch *ds, int port,