ARM: OMAP1: ams-delta: fix early boot crash when LED support is disabled

When we boot with the LED support (CONFIG_NEW_LEDS) disabled,
gpio_led_register_device() will return a NULL pointer and we try
to dereference it. Fix by checking also for a NULL pointer.

Fixes: 19a2668a ("ARM: OMAP1: ams-delta: Provide GPIO lookup table for LED device")
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap1/board-ams-delta.c

@@ -749,7 +749,7 @@ static void __init ams_delta_init(void)
 				ARRAY_SIZE(ams_delta_gpio_tables));
 
 	leds_pdev = gpio_led_register_device(PLATFORM_DEVID_NONE, &leds_pdata);
-	if (!IS_ERR(leds_pdev)) {
+	if (!IS_ERR_OR_NULL(leds_pdev)) {
 		leds_gpio_table.dev_id = dev_name(&leds_pdev->dev);
 		gpiod_add_lookup_table(&leds_gpio_table);
 	}