net: bcmgenet: Check for Wake-on-LAN interrupt probe deferral

The interrupt controller supplying the Wake-on-LAN interrupt line maybe
modular on some platforms (irq-bcm7038-l1.c) and might be probed at a
later time than the GENET driver. We need to specifically check for
-EPROBE_DEFER and propagate that error to ensure that we eventually
fetch the interrupt descriptor.

Fixes: 9deb48b ("bcmgenet: add WOL IRQ check")
Fixes: 5b1f0e6 ("net: bcmgenet: Avoid touching non-existent interrupt")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/20220511031752.2245566-1-f.fainelli@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: ffainelli

drivers/net/ethernet/broadcom/genet/bcmgenet.c

@@ -3999,6 +3999,10 @@ static int bcmgenet_probe(struct platform_device *pdev)
 		goto err;
 	}
 	priv->wol_irq = platform_get_irq_optional(pdev, 2);
+	if (priv->wol_irq == -EPROBE_DEFER) {
+		err = priv->wol_irq;
+		goto err;
+	}
 
 	priv->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(priv->base)) {