Input: handle serio_register_driver() errors

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/keyboard/newtonkbd.c b/drivers/input/keyboard/newtonkbd.c
index 33e8139..aa29b50 100644
--- a/drivers/input/keyboard/newtonkbd.c
+++ b/drivers/input/keyboard/newtonkbd.c
@@ -169,8 +169,7 @@
 
 static int __init nkbd_init(void)
 {
-	serio_register_driver(&nkbd_drv);
-	return 0;
+	return serio_register_driver(&nkbd_drv);
 }
 
 static void __exit nkbd_exit(void)