Fix an off-by-one in zyd_rxeof(). ok krw@ kettenis@ mpi@
Fix an off-by-one in zyd_rxeof().
ok krw@ kettenis@ mpi@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars