HID: asus: Ignore Asus vendor-page usage-code 0xff events

At least on a T100HA an Asus vendor-page usage-code 0xff event is send on
every suspend and again on resume, resulting in the following warning:

asus 0003:0B05:1807.0002: Unmapped Asus vendor usagepage code 0xff

being logged twice on every suspend/resume.

This commit silences the "Unmapped Asus vendor usagepage code ..."
warning for usage-code 0xff to avoid these warnings being logged.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-asus.c

@@ -261,7 +261,8 @@ static int asus_event(struct hid_device *hdev, struct hid_field *field,
 		      struct hid_usage *usage, __s32 value)
 {
 	if ((usage->hid & HID_USAGE_PAGE) == 0xff310000 &&
-	    (usage->hid & HID_USAGE) != 0x00 && !usage->type) {
+	    (usage->hid & HID_USAGE) != 0x00 &&
+	    (usage->hid & HID_USAGE) != 0xff && !usage->type) {
 		hid_warn(hdev, "Unmapped Asus vendor usagepage code 0x%02x\n",
 			 usage->hid & HID_USAGE);
 	}