mkfs: Reduce disk image size from 128M to 16M
mkfs: Reduce disk image size from 128M to 16M

I think the 128M was an accident when I changed everything from 512
byte sectors to 4K blocks.

aclements/sv6,bowlofstew/sv6,aclements/sv6,aclements/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,bowlofstew/sv6,bowlofstew/sv6,aclements/sv6