power: reset: mt6397: Check for null res pointer

The return value of platform_get_resource() needs to be checked.
To avoid use of error pointer in case that there is no suitable
resource.

Fixes: d28c74c1 ("power: reset: add driver for mt6323 poweroff")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/reset/mt6323-poweroff.c

@@ -57,6 +57,9 @@ static int mt6323_pwrc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
 	pwrc->base = res->start;
 	pwrc->regmap = mt6397_chip->regmap;
 	pwrc->dev = &pdev->dev;