Automatic merge from submit-queue (batch tested with PRs 41337, 41375, 41363, 41034, 41350)
kubeadm: adding tests for util/tokens.go
**What this PR does / why we need it**: added tests to util pkg and raised coverage from ~48% to ~67%. Will get better coverage once migration to client-go is complete. Included a fix for a logic error in tokens.go found through writing tests
Adding unit tests is a WIP from #34136
**Special notes for your reviewer**: /cc @luxas @pires
**Release note**:
```release-note
NONE
```