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

This converts the drivers in drivers/usb/* 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: Simon Arlott <cxacru@fire.lp0.eu>
Cc: Duncan Sands <duncan.sands@free.fr>
Cc: Matthieu CASTET <castet.matthieu@free.fr>
Cc: Stanislaw Gruszka <stf_xl@wp.pl>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: Juergen Stuber <starblue@users.sourceforge.net>
Cc: Cesar Miquel <miquel@df.uba.ar>
Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Michael Hund <mhund@ld-didactic.de>
Cc: Zack Parsons <k3bacon@gmail.com>
Cc: Melchior FRANZ <mfranz@aon.at>
Cc: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/wusbcore/cbaf.c b/drivers/usb/wusbcore/cbaf.c
index 200fd7c..7f78f30 100644
--- a/drivers/usb/wusbcore/cbaf.c
+++ b/drivers/usb/wusbcore/cbaf.c
@@ -655,17 +655,7 @@
 	.disconnect =	cbaf_disconnect,
 };
 
-static int __init cbaf_driver_init(void)
-{
-	return usb_register(&cbaf_driver);
-}
-module_init(cbaf_driver_init);
-
-static void __exit cbaf_driver_exit(void)
-{
-	usb_deregister(&cbaf_driver);
-}
-module_exit(cbaf_driver_exit);
+module_usb_driver(cbaf_driver);
 
 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
 MODULE_DESCRIPTION("Wireless USB Cable Based Association");