stdenv/check-meta: move negation outside loop, avoid primop if undefined

  checkOutputsToInstall =

    attrs:

    attrs.meta ? outputsToInstall

    && (

      let

        actualOutputs = attrs.outputs or [ "out" ];

      in

    any (output: !elem output actualOutputs) (attrs.meta.outputsToInstall or [ ]);

      !all (output: elem output actualOutputs) attrs.meta.outputsToInstall

    );

  # Check if a derivation is valid, that is whether it passes checks for

  # e.g brokenness or license.