netlink_delinearize: only remove protocol if equal cmp is used

netlink_delinearize: only remove protocol if equal cmp is used

Check for OP_EQ before removing a dependency, else we may zap wrong one,
changing the meaning of the rule.

Listing without patch:
ip protocol udp udp dport ssh
ip protocol udp udp dport ssh
counter packets 1 bytes 308 ip protocol udp udp dport ssh

With patch:
ip protocol != tcp udp dport ssh
ip protocol != udp udp dport ssh
ip protocol != tcp counter packets 1 bytes 308 udp dport ssh

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>