isisd: do remove ipv6 routes from Zebra

We can abort isis_zebra_route_del_ipv6 if the route in question has
ISIS_ROUTE_FLAG_ZEBRA_SYNCED unset, meaning it's not in the kernel.
Aborting the function if the flag is set prevents us from removing
any routes.

Signed-off-by: Christian Franke <chris@opensourcerouting.org>
Acked-by: Donald Sharp <sharpd@cumulusnetworks.com>
1 file changed