zebra: remove unused netlink_route()/kernel_rtm_ipv6()

kernel_delete_ipv6_old(), removed in 51bdeba a little while ago, was the
last user of netlink_route() and kernel_rtm_ipv6().  Everything else
uses the _multipath variants of these functions.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
2 files changed