This fixes compile error when CONFIG_NET_NS is not set.
Introduced by:
commit 1d4c8c29841b9991cdf3c7cc4ba7f96a94f104ca
"neigh: restore old behaviour of default parms values"
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>