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 <[e-mail]>
Reviewed-by: Guenter Roeck <[e-mail]>
Signed-off-by: Guenter Roeck <[e-mail]>
Signed-off-by: Wim Van Sebroeck <[e-mail]>

drivers/watchdog/qcom-wdt.c

···
 		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))