Automatic merge from submit-queue

Both the file name and directory of fake docker manager are wrong

In file "docs/devel/kubemark-guide.md b/docs/devel/kubemark-guide.md", line 232
"manager with `pkg/kubelet/fake-docker-manager.go`"
here both the name and directory of fake docker manger are wrong, it should be "pkg/kubelet/dockertools/fake_manager.go".