gigaset: avoid registering CAPI driver more than once

Registering/unregistering the Gigaset CAPI driver when a device is
connected/disconnected causes an Oops when disconnecting two Gigaset
devices in a row, because the same capi_driver structure gets
unregistered twice. Fix by making driver registration/unregistration
a separate operation (empty in the ISDN4Linux case) called when the
main module is loaded/unloaded.

Impact: bugfix
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Acked-by: Karsten Keil <keil@b1-systems.de>
CC: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index 1875ab8..cdd144e 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -675,8 +675,10 @@
  */
 
 /* Called from common.c for setting up/shutting down with the ISDN subsystem */
-int gigaset_isdn_register(struct cardstate *cs, const char *isdnid);
-void gigaset_isdn_unregister(struct cardstate *cs);
+void gigaset_isdn_regdrv(void);
+void gigaset_isdn_unregdrv(void);
+int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid);
+void gigaset_isdn_unregdev(struct cardstate *cs);
 
 /* Called from hardware module to indicate completion of an skb */
 void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *skb);