Use 12 and 16 byte read/write commands as required by the size/length of the I/O being attempted. Throw in a comment typo fix to properly refer to sectors and not blocks.
Use 12 and 16 byte read/write commands as required by the size/length
of the I/O being attempted. Throw in a comment typo fix to properly
refer to sectors and not blocks.

ok marco@

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