fib/netdev cleanup

[Julian Anastasov <ja@xxxxxx>]

        Hello,

        I see some problems with the netdev notifications for
the FIB:

1. fib_inetaddr_event deletes all routes when the last address is
deleted which is wrong, may be because there is the 2nd problem:

2. FIB never detects NETDEV_UNREGISTER because ip_ptr is already NULL

3. We better to clear nh->nh_dev on NETDEV_UNREGISTER, fatal for
multipath routes in 2.4 (problem known from some time ago)

I uploaded all these changes, both for 2.2 and 2.4 here:

http://www.linuxvirtualserver.org/~julian/fibnetdev-2.4.16-1.diff
http://www.linuxvirtualserver.org/~julian/fibnetdev-2.2.20-1.diff

Regards

--
Julian Anastasov <ja@xxxxxx>