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

This converts the drivers in drivers/input/* 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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Ville Syrjala <syrjala@sci.fi>
Cc: Henk Vergonet <Henk.Vergonet@gmail.com>
Cc: Alessandro Rubini <rubini@ipvvis.unipv.it>
Cc: Henrik Rydberg <rydberg@euromail.se>
Cc: "Magnus Hörlin" <magnus@alefors.se>
Cc: Chris Moeller <kode54@gmail.c>
Cc: Christoph Fritz <chf.fritz@googlemail.com>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Edwin van Vliet <edwin@cheatah.nl>
Cc: Ping Cheng <pingc@wacom.com>
Cc: Eduard Hasenleithner <eduard@hasenleithner.at>
Cc: Alexander Strakh <strakh@ispras.ru>
Cc: Glenn Sommer <gsommer@datanordisk.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index 1c1b7b4..8f9cde3 100644
--- a/drivers/input/tablet/wacom_sys.c
+++ b/drivers/input/tablet/wacom_sys.c
@@ -919,21 +919,4 @@
 	.supports_autosuspend = 1,
 };
 
-static int __init wacom_init(void)
-{
-	int result;
-
-	result = usb_register(&wacom_driver);
-	if (result == 0)
-		printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
-		       DRIVER_DESC "\n");
-	return result;
-}
-
-static void __exit wacom_exit(void)
-{
-	usb_deregister(&wacom_driver);
-}
-
-module_init(wacom_init);
-module_exit(wacom_exit);
+module_usb_driver(wacom_driver);