asus-wmi: return proper value in store_cpufv()

Cc: stable@kernel.org
Signed-off-by: Corentin Chary <corentin.chary@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/asus-wmi.c

@@ -1307,14 +1307,18 @@ ASUS_WMI_CREATE_DEVICE_ATTR(cardr, 0644, ASUS_WMI_DEVID_CARDREADER);
 static ssize_t store_cpufv(struct device *dev, struct device_attribute *attr,
 			   const char *buf, size_t count)
 {
-	int value;
+	int value, rv;
 
 	if (!count || sscanf(buf, "%i", &value) != 1)
 		return -EINVAL;
 	if (value < 0 || value > 2)
 		return -EINVAL;
 
-	return asus_wmi_evaluate_method(ASUS_WMI_METHODID_CFVS, value, 0, NULL);
+	rv = asus_wmi_evaluate_method(ASUS_WMI_METHODID_CFVS, value, 0, NULL);
+	if (rv < 0)
+		return rv;
+
+	return count;
 }
 
 static DEVICE_ATTR(cpufv, S_IRUGO | S_IWUSR, NULL, store_cpufv);