This fixes golint failures on the following files:
- test/e2e/framework/deployment_util.go
- test/e2e/framework/exec_util.go

Cleanup:
- ScaleDeployment() was not used at all, so let's remove it.
- ExecCommandInPod() and ExecCommandInPodWithFullOutput() were called
  in the framework only, so let's make them local.