driver-core: platform: Catch errors from calls to irq_get_irq_data

irq_get_irq_data() can return NULL, which results in a nasty crash.
Check its return value before passing it on to irqd_set_trigger_type().

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/platform.c

@@ -108,9 +108,14 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
 	 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
 	 * settings.
 	 */
-	if (r && r->flags & IORESOURCE_BITS)
-		irqd_set_trigger_type(irq_get_irq_data(r->start),
-				      r->flags & IORESOURCE_BITS);
+	if (r && r->flags & IORESOURCE_BITS) {
+		struct irq_data *irqd;
+
+		irqd = irq_get_irq_data(r->start);
+		if (!irqd)
+			return -ENXIO;
+		irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
+	}
 
 	return r ? r->start : -ENXIO;
 #endif