pf: Free pf_rule_items when state is not created

[vegeta_tuxpowered.net]

Summary

This addresses the issues of pf_rule_times leaking in case of stateless rules and in case of state creation failures, like hitting the state limit.

Sponsored by: InnoGames GmbH

Test Plan

I've created a rulesets with a match rule and with a pass rule with state limit or with no state. After sending a few packets through I've unloaded pf.ko and that resulted with memory leak being logged. With this patch the leak is not logged anymore.