problems building on kernel 2.6

It seems that the minix filesystem has subtle bugs on 2.6,
such that "du" no longer returns anything nearly correct.

This is causing tomsrtbt not to build on 2.6, as it bases
filesystem sizes on "du" results.  I'm not sure there is
any easy workaround without hacking up buildit.s to use
hardcoded values or something, I'm still investigating.

-Tom