Try harder to ensure wddump() doesn't decrement the count of sectors to write by one value and increment the address the next i/o will start at by a different amount.
Try harder to ensure wddump() doesn't decrement the count
of sectors to write by one value and increment the address
the next i/o will start at by a different amount.

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