mfd: Don't use NO_IRQ in WM8350

NO_IRQ is only defined on some architectures - the general way to test
for an invalid IRQ in the modern kernel is by comparing with zero.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>

drivers/mfd/wm8350-core.c

@@ -1217,7 +1217,7 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq,
 
 	mutex_init(&wm8350->irq_mutex);
 	INIT_WORK(&wm8350->irq_work, wm8350_irq_worker);
-	if (irq != NO_IRQ) {
+	if (irq) {
 		ret = request_irq(irq, wm8350_irq, 0,
 				  "wm8350", wm8350);
 		if (ret != 0) {