HID: multitouch: Apply MT_QUIRK_CONFIDENCE quirk for multi-input devices

commit 794c613 upstream.

Palm ejection stops working on some Elan and Synaptics touchpad after
commit 40d5bb8 ("HID: multitouch: enable multi-input as a quirk for
some devices").

The commit changes the mt_class from MT_CLS_WIN_8 to
MT_CLS_WIN_8_FORCE_MULTI_INPUT, so MT_QUIRK_CONFIDENCE isn't applied
anymore.

So also apply the quirk since MT_CLS_WIN_8_FORCE_MULTI_INPUT is
essentially MT_CLS_WIN_8.

Fixes: 40d5bb8 ("HID: multitouch: enable multi-input as a quirk for some devices")
Cc: stable@vger.kernel.org
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hid/hid-multitouch.c

@@ -758,7 +758,8 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 			MT_STORE_FIELD(inrange_state);
 			return 1;
 		case HID_DG_CONFIDENCE:
-			if (cls->name == MT_CLS_WIN_8 &&
+			if ((cls->name == MT_CLS_WIN_8 ||
+			     cls->name == MT_CLS_WIN_8_FORCE_MULTI_INPUT) &&
 				(field->application == HID_DG_TOUCHPAD ||
 				 field->application == HID_DG_TOUCHSCREEN))
 				app->quirks |= MT_QUIRK_CONFIDENCE;