ohash expects the keys to be laid out in memory, it can't follow pointers. So, convert the key pointer to a flexible array memer at the end of the kp struct. Enojoy O(1) again!

I don't know what I'm doing wrong with ohash. It just can't find anything. Since I have other things to do, for the time being revert to a linear search. O(1) is better than O(n) that is better than broken O(1), amrite?