Fix golint failures of pkg/kubelet/dockershim/cm

hack/.golint_failures

@@ -178,7 +178,6 @@ pkg/kubelet/container
 pkg/kubelet/container/testing
 pkg/kubelet/custommetrics
 pkg/kubelet/dockershim
-pkg/kubelet/dockershim/cm
 pkg/kubelet/dockershim/libdocker
 pkg/kubelet/dockershim/network
 pkg/kubelet/dockershim/network/cni

pkg/kubelet/dockershim/cm/container_manager.go

@@ -16,6 +16,8 @@ limitations under the License.
 
 package cm
 
+// ContainerManager is an interface that abstracts the basic operations of a
+// container manager.
 type ContainerManager interface {
 	Start() error
 }

pkg/kubelet/dockershim/cm/container_manager_linux.go

@@ -51,6 +51,7 @@ var (
 	memoryCapacityRegexp = regexp.MustCompile(`MemTotal:\s*([0-9]+) kB`)
 )
 
+// NewContainerManager creates a new instance of ContainerManager
 func NewContainerManager(cgroupsName string, client libdocker.Interface) ContainerManager {
 	return &containerManager{
 		cgroupsName: cgroupsName,

pkg/kubelet/dockershim/cm/container_manager_unsupported.go

@@ -27,6 +27,7 @@ import (
 type unsupportedContainerManager struct {
 }
 
+// NewContainerManager creates a new instance of ContainerManager
 func NewContainerManager(_ string, _ libdocker.Interface) ContainerManager {
 	return &unsupportedContainerManager{}
 }

pkg/kubelet/dockershim/cm/container_manager_windows.go

@@ -26,6 +26,7 @@ import (
 type containerManager struct {
 }
 
+// NewContainerManager creates a new instance of ContainerManager
 func NewContainerManager(_ string, _ libdocker.Interface) ContainerManager {
 	return &containerManager{}
 }