Add checks for sector-alignment and whole number of sectors to bounds_check_with_label() and generally cleanup the code while here.
Add checks for sector-alignment and whole number of sectors to
bounds_check_with_label() and generally cleanup the code while here.

ok krw@ ("I like this a *lot*"); "i like it" tedu@

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