regulator: rt4801: Fix NULL pointer dereference if priv->enable_gpios is NULL

devm_gpiod_get_array_optional may return NULL if no GPIO was assigned.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20210603094944.1114156-1-axel.lin@ingics.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/rt4801-regulator.c

@@ -66,7 +66,7 @@ static int rt4801_enable(struct regulator_dev *rdev)
 	struct gpio_descs *gpios = priv->enable_gpios;
 	int id = rdev_get_id(rdev), ret;
 
-	if (gpios->ndescs <= id) {
+	if (!gpios || gpios->ndescs <= id) {
 		dev_warn(&rdev->dev, "no dedicated gpio can control\n");
 		goto bypass_gpio;
 	}
@@ -88,7 +88,7 @@ static int rt4801_disable(struct regulator_dev *rdev)
 	struct gpio_descs *gpios = priv->enable_gpios;
 	int id = rdev_get_id(rdev);
 
-	if (gpios->ndescs <= id) {
+	if (!gpios || gpios->ndescs <= id) {
 		dev_warn(&rdev->dev, "no dedicated gpio can control\n");
 		goto bypass_gpio;
 	}