Merge pull request #35884 from foxyriver/exchange

Automatic merge from submit-queue

print log error

<!--  Thanks for sending a pull request!  Here are some tips for you:
1. If this is your first time, read our contributor guidelines https://github.com/kubernetes/kubernetes/blob/master/CONTRIBUTING.md and developer guide https://github.com/kubernetes/kubernetes/blob/master/docs/devel/development.md
2. If you want *faster* PR reviews, read how: https://github.com/kubernetes/kubernetes/blob/master/docs/devel/faster_reviews.md
3. Follow the instructions for writing a release note: https://github.com/kubernetes/kubernetes/blob/master/docs/devel/pull-requests.md#release-notes
-->

**What this PR does / why we need it**:

when failed to load CA,will print both "Loaded CA:" and "Error loading root CA certificate date:" ,but only need to print "Error loading root CA certificate date:" in fact.

**Special notes for your reviewer**:

**Release note**:

<!--  Steps to write your release note:
1. Use the release-note-* labels to set the release note state (if you have access) 
2. Enter your extended release note in the below block; leaving it blank means using the PR title as the release note. If no release note is required, just write `NONE`. 
-->

``` release-note
```
This commit is contained in:
Kubernetes Submit Queue 2016-12-08 03:29:41 -08:00 committed by GitHub
commit 47181133c1

View File

@ -141,13 +141,13 @@ func (cih *ClusterInfoHandler) ServeHTTP(resp http.ResponseWriter, req *http.Req
// TODO probably should not leak server-side errors to the client
caPEM, err := cih.caLoader.LoadPEM()
log.Printf("Loaded CA: %s", caPEM)
if err != nil {
err = fmt.Errorf("Error loading root CA certificate data: %s", err)
log.Println(err)
http.Error(resp, err.Error(), http.StatusInternalServerError)
return
}
log.Printf("Loaded CA: %s", caPEM)
endpoints, err := cih.endpointsLoader.LoadList()
if err != nil {