k8s.io: fix shellcheck failures
k8s.io: fix shellcheck failures

failures addressed:
- SC2166: Prefer [ p ] || [ q ] as [ p -o q ] is not well defined.
- SC2162: read without -r will mangle backslashes.

kubernetes/k8s.io,kubernetes/k8s.io,kubernetes/k8s.io,kubernetes/k8s.io