make verify codegen macosx compatible

[k-wall]

Type of change

• Bugfix

Description

Make build-time utility script run on Mac OS X.

Checklist

• [ ] Update/write design documentation in ./documentation/design
• [ ] Write tests and make sure they pass
• [ ] Update documentation
• [ ] Check RBAC rights for Kubernetes / OpenShift roles
• [ ] Try your changes from Pod inside your Kubernetes and OpenShift cluster, not just locally
• [ ] Reference relevant issue(s) and close them after merging
• [ ] Update CHANGELOG.md