pinctrl: exynos: Fix wakeup IRQ domain registration check

Because of a typo, incorrect field of a structure was being checked.
This patch fixes the check to use correct field.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/drivers/pinctrl/pinctrl-exynos.c b/drivers/pinctrl/pinctrl-exynos.c
index 0d01d19..21362f4 100644
--- a/drivers/pinctrl/pinctrl-exynos.c
+++ b/drivers/pinctrl/pinctrl-exynos.c
@@ -447,7 +447,7 @@
 
 	d->wkup_irqd = irq_domain_add_linear(wkup_np, d->ctrl->nr_wint,
 				&exynos_wkup_irqd_ops, d);
-	if (!d->gpio_irqd) {
+	if (!d->wkup_irqd) {
 		dev_err(dev, "wakeup irq domain allocation failed\n");
 		return -ENXIO;
 	}