watchdog: qcom: Check for platform_get_resource() failure

platform_get_resource() may fail, so we should better check its
return value and propagate an error in case it fails.

This avoids a NULL pointer dereference a bit later in the code.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
index 4f47b5e..7809713 100644
--- a/drivers/watchdog/qcom-wdt.c
+++ b/drivers/watchdog/qcom-wdt.c
@@ -162,6 +162,8 @@
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOMEM;
 
 	/* We use CPU0's DGT for the watchdog */
 	if (of_property_read_u32(np, "cpu-offset", &percpu_offset))