[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>