[PATCH] Allow changing `creator_net` after interface creation.

[Jason A. Donenfeld]

Hey Maarten,

Thanks for the patch. It turns out that in the git repo, the
jo/transit-namespace branch from Julian (CC'd) already has something
that seems very familiar with this. Pending upstreaming, we're holding
off on adding new features, but following that, we'll start to
evaluate options like this very seriously.

Do you see a difference between what your patchset does and what Julian's does?

Jason