HID: multitouch: Synchronize MT frame on reset_resume

input_mt_get_slot_by_key() requires input_mt_sync_frame() to be called
at each frame. Do it when releasing the touches, or else we won't get
a proper slot number after mt_reset_resume().
Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Benjamin TIssoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-multitouch.c

@@ -1169,6 +1169,7 @@ static void mt_release_contacts(struct hid_device *hid)
 							   MT_TOOL_FINGER,
 							   false);
 			}
+			input_mt_sync_frame(input_dev);
 			input_sync(input_dev);
 		}
 	}