Input: tps6507x-ts - properly unregister input device on removal

Once device is registered we should call input_unregister_device()
instead of input_free_device().

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/tps6507x-ts.c b/drivers/input/touchscreen/tps6507x-ts.c
index 7286209..c8c136c 100644
--- a/drivers/input/touchscreen/tps6507x-ts.c
+++ b/drivers/input/touchscreen/tps6507x-ts.c
@@ -359,7 +359,7 @@
 	cancel_delayed_work_sync(&tsc->work);
 	destroy_workqueue(tsc->wq);
 
-	input_free_device(input_dev);
+	input_unregister_device(input_dev);
 
 	tps6507x_dev->ts = NULL;
 	kfree(tsc);