net/smsc911x: Fix deferred probe for interrupt

The interrupt handler may not be available when smsc911x probes if the
interrupt handler is a GPIO controller for example. Let's fix that
by adding handling for -EPROBE_DEFER.

Cc: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/smsc/smsc911x.c

@@ -2435,7 +2435,10 @@ static int smsc911x_drv_probe(struct platform_device *pdev)
 	res_size = resource_size(res);
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq <= 0) {
+	if (irq == -EPROBE_DEFER) {
+		retval = -EPROBE_DEFER;
+		goto out_0;
+	} else if (irq <= 0) {
 		pr_warn("Could not allocate irq resource\n");
 		retval = -ENODEV;
 		goto out_0;