Re: randomise arc4random() rekey interval

[Theo de Raadt]

+       rs->rs_count += rekey_fuzz & (REKEY_BASE - 1);

I mean, why not use % here

And then, set the default to a pow2.

But if someone changes it to not pow2, it still works.

The & is premature hand-optimization, let a compiler do it if it can.