netfilter: ipset: fix ip_set_flush return code

ip_set_flush returned -EPROTO instead of -IPSET_ERR_PROTOCOL, fixed

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1 file changed