Use nexthop_for_each_fib6_nh and fib6_nh_find_match to find the
fib6_nh in a nexthop that correlates to the device and gateway
in the rt6_info.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>