The "misc" NixOS test is using Nix to query the store and it tries to
change the ownership of it while doing so.
This fails if Nix is not in a seccomp-sandboxed userid namespace, so
let's make chown() a no-op when applied to store paths.
Fixes the misc test (and possibly future tests) on older Nix versions.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
38ea64e867