Automatic merge from submit-queue
Fix sort-by output problem
Fixes https://github.com/kubernetes/kubectl/issues/43
This bug was original introduced in pr here: https://github.com/kubernetes/kubernetes/pull/46265, I think next time if we touch something printer related package, maybe should let @smarterclayton have a review, although he is pretty busy I guess : ) and that package also changed a lot recently since he's been working on refactoring.
this is a quick and dirty fix, not sure if there's better way, I will add some regression test soon...
@kubernetes/sig-cli-pr-reviews
```release-note
NONE
```
/assign @mengqiy
/assign @smarterclayton
190ee708a6