Index: sys/dev/superio/superio.c
===================================================================
--- sys/dev/superio/superio.c
+++ sys/dev/superio/superio.c
@@ -413,6 +413,7 @@
 	case SUPERIO_DEV_GPIO:
 		return ("GPIO");
 	case SUPERIO_DEV_MAX:
+	default:
 		return ("invalid");
 	}
 }