extcon: max77693: fix handling return value of regmap_irq_get_virq

The function can return negative values, so its result should
be assigned to signed variable.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Suggested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
diff --git a/drivers/extcon/extcon-max77693.c b/drivers/extcon/extcon-max77693.c
index 44c499e..fdf8f5d 100644
--- a/drivers/extcon/extcon-max77693.c
+++ b/drivers/extcon/extcon-max77693.c
@@ -1127,11 +1127,11 @@
 	/* Support irq domain for MAX77693 MUIC device */
 	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++) {
 		struct max77693_muic_irq *muic_irq = &muic_irqs[i];
-		unsigned int virq = 0;
+		int virq;
 
 		virq = regmap_irq_get_virq(max77693->irq_data_muic,
 					muic_irq->irq);
-		if (!virq)
+		if (virq <= 0)
 			return -EINVAL;
 		muic_irq->virq = virq;