Don't change directory owner to root when building with -DNO_ROOT

[arichardson]

Summary

Currently the mtree calls in Makefile.inc1 all change the directory owner
to match the spec file. However, we should not be doing this during
distributeworld if -DNO_ROOT is passed. Additionally, when creating the
WORLDTMP directory hierachy there is no need to change the owner to root so
we now always pass the -W flag when populating WORLDTMP.

This is also required for building FreeBSD on Linux/Mac since the required
groups/users will not exist there which is how I discovered this issue.

[emaste]

LGTM, would like to see ideally @bdrewery but at least someone else agree

[imp]

Looks good to me. Thanks for splitting it out. There's no huge rush, so I'd make sure that bdrewery signs off as well.

[arichardson]

@bdrewery does this look okay?

[bdrewery]

In D14185#314787, @arichardson wrote:

@bdrewery does this look okay?

Yup. I am flooded with random phab reviews that are not really for me due to ports. Sorry...