of: irq: fix of_irq_to_resource() error check

of_irq_to_resource() has recently been fixed to return negative error #'s
along with 0, however of_irq_to_resource_table() still only regards 0 as
invalid IRQ -- fix it up.

Fixes: 7a4228b ("of: irq: use of_irq_get() in of_irq_to_resource()")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/irq.c

@@ -476,7 +476,7 @@ int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
 	int i;
 
 	for (i = 0; i < nr_irqs; i++, res++)
-		if (!of_irq_to_resource(dev, i, res))
+		if (of_irq_to_resource(dev, i, res) <= 0)
 			break;
 
 	return i;