Input: gameport - make gameport_bus const

Now that the driver core can properly handle constant struct bus_type,
move the gameport_bus variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240204-bus_cleanup-input-v1-1-74c2438801cf@marliere.netSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/gameport/gameport.c

@@ -38,7 +38,7 @@ static DEFINE_MUTEX(gameport_mutex);
 
 static LIST_HEAD(gameport_list);
 
-static struct bus_type gameport_bus;
+static const struct bus_type gameport_bus;
 
 static void gameport_add_port(struct gameport *gameport);
 static void gameport_attach_driver(struct gameport_driver *drv);
@@ -813,7 +813,7 @@ static int gameport_bus_match(struct device *dev, struct device_driver *drv)
 	return !gameport_drv->ignore;
 }
 
-static struct bus_type gameport_bus = {
+static const struct bus_type gameport_bus = {
 	.name		= "gameport",
 	.dev_groups	= gameport_device_groups,
 	.drv_groups	= gameport_driver_groups,