[PATCH] isdn: fix missing unregister_capi_driver

unregister_capi_driver() needs to be called in module cleanup.
(It fixes data corruption by reloading t1isa driver)

Cc: Kai Germaschewski <kai.germaschewski@gmx.de>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/isdn/hardware/avm/t1isa.c

@@ -584,6 +584,7 @@ static void __exit t1isa_exit(void)
 {
 	int i;
 
+	unregister_capi_driver(&capi_driver_t1isa);
 	for (i = 0; i < MAX_CARDS; i++) {
 		if (!io[i])
 			break;