HID: wacom: put the managed resources in a group

We currently have a complex clean_inputs() function while this can be
handled all by devres. Set a group that we can destroy in wireless_work().

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index c7707b2..3e2c903 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -1941,7 +1941,7 @@
 	}
 
 	/* only update touch if we actually have a touchpad and touch data changed */
-	if (wacom->touch_registered && touch_changed) {
+	if (wacom->touch_input && touch_changed) {
 		input_mt_sync_frame(wacom->touch_input);
 		wacom->shared->touch_down = wacom_wac_finger_count_touches(wacom);
 	}