asus-laptop: return proper error for store_ledd if write_acpi_int fail

In current implementation, store_ledd() does not return error if
write_acpi_int fail.  This patch fixes it by return -ENODEV if
write_acpi_int fail.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/asus-laptop.c

@@ -796,10 +796,11 @@ static ssize_t store_ledd(struct device *dev, struct device_attribute *attr,
 
 	rv = parse_arg(buf, count, &value);
 	if (rv > 0) {
-		if (write_acpi_int(asus->handle, METHOD_LEDD, value))
+		if (write_acpi_int(asus->handle, METHOD_LEDD, value)) {
 			pr_warning("LED display write failed\n");
-		else
-			asus->ledd_status = (u32) value;
+			return -ENODEV;
+		}
+		asus->ledd_status = (u32) value;
 	}
 	return rv;
 }