net: dsa: bcm_sf2: Unwind errors in correct order

In case we cannot complete bcm_sf2_sw_setup() for any reason, and we
go to the out_unmap label, but the MDIO bus has not been registered yet,
we will hit the BUG condition in drivers/net/phy/mdio_bus.c about the
bus not being registered. Fix this by dedicating a specific lable for
when we fail after the MDIO bus has been successfully registered.

Fixes: 461cd1b03e32 ("net: dsa: bcm_sf2: Register our slave MDIO bus")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/bcm_sf2.c

@@ -1622,7 +1622,7 @@ static int bcm_sf2_sw_setup(struct dsa_switch *ds)
 			  "switch_0", priv);
 	if (ret < 0) {
 		pr_err("failed to request switch_0 IRQ\n");
-		goto out_unmap;
+		goto out_mdio;
 	}
 
 	ret = request_irq(priv->irq1, bcm_sf2_switch_1_isr, 0,
@@ -1679,6 +1679,8 @@ static int bcm_sf2_sw_setup(struct dsa_switch *ds)
 
 out_free_irq0:
 	free_irq(priv->irq0, priv);
+out_mdio:
+	bcm_sf2_mdio_unregister(priv);
 out_unmap:
 	base = &priv->core;
 	for (i = 0; i < BCM_SF2_REGS_NUM; i++) {
@@ -1686,7 +1688,6 @@ out_unmap:
 			iounmap(*base);
 		base++;
 	}
-	bcm_sf2_mdio_unregister(priv);
 	return ret;
 }