Use atop() and ptoa() in buf_free_pages() to make it consistent with the rest of the code, okay art@.
Use atop() and ptoa() in buf_free_pages() to make it consistent with
the rest of the code, okay art@.

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