media: platform: Use gpio_is_valid()

Replace the manual validity checks for the GPIO with the
gpio_is_valid().
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/via-camera.c

@@ -178,7 +178,7 @@ static int via_sensor_power_setup(struct via_camera *cam)
 
 	cam->power_gpio = viafb_gpio_lookup("VGPIO3");
 	cam->reset_gpio = viafb_gpio_lookup("VGPIO2");
-	if (cam->power_gpio < 0 || cam->reset_gpio < 0) {
+	if (!gpio_is_valid(cam->power_gpio) || !gpio_is_valid(cam->reset_gpio)) {
 		dev_err(&cam->platdev->dev, "Unable to find GPIO lines\n");
 		return -EINVAL;
 	}