modules/zsh: Fix evaluation error and clean up

Regression introduced by 25a077f90a0005b519db071a6b5b4d20bd6d2d45.

I usually let Vim perform a syntax check on the Nix file I'm editing,
which usually displays errors. However, given that the zsh module is one
of my older modules where I did a big "with lib;" over the whole scope,
a nix-instantiate --parse didn't find the missing pkgs argument.

So apart from just fixing the error, I removed the "with lib;" and also
moved from the old lib.overrideDerivation to package.overrideAttrs.

Signed-off-by: aszlig <aszlig@nix.build>

0 files changed, 0 insertions, 0 deletions