Automatic merge from submit-queue
remove call to compinit in zsh completion output
**Release note**:
```release-note
release-note-none
```
Fixes: https://github.com/kubernetes/kubernetes/issues/32029
Fixes:
https://github.com/kubernetes/kubernetes/issues/27538#issuecomment-238574035
The zsh completion output makes a call to "compinit" which causes the
zsh completion system to re-initialize every time `<root_cmd> completion zsh`
is sourced, overwriting any settings already applied to other commands.
This in-turn caused other commands' completions to break (such as git,
gcloud, vim) causing an error "function definition file not found" to
be returned any time a tab-completion was attempted.
This patch removes the call to `compinit` in the zsh completion output,
causing no behavioral changes to the existing `completion` command, but
fixing any issues that were caused after sourcing its output.
786cc3ef6c