USB: convert drivers/bluetooth/* to use module_usb_driver()

This converts the drivers in drivers/bluetooth/* to use the
module_usb_driver() macro which makes the code smaller and a bit
simpler.

Added bonus is that it removes some unneeded kernel log messages about
drivers loading and/or unloading.

Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: "Gustavo F. Padovan" <padovan@profusion.mobi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index f9b7260..b0e6d8d 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -1220,20 +1220,7 @@
 	.supports_autosuspend = 1,
 };
 
-static int __init btusb_init(void)
-{
-	BT_INFO("Generic Bluetooth USB driver ver %s", VERSION);
-
-	return usb_register(&btusb_driver);
-}
-
-static void __exit btusb_exit(void)
-{
-	usb_deregister(&btusb_driver);
-}
-
-module_init(btusb_init);
-module_exit(btusb_exit);
+module_usb_driver(btusb_driver);
 
 module_param(ignore_dga, bool, 0644);
 MODULE_PARM_DESC(ignore_dga, "Ignore devices with id 08fd:0001");