cgroups/fs/Freeze: simplify

In here, defer looks like an overkill, since the code is very simple and
we already have an error path.

Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

libcontainer/cgroups/fs/fs.go

@@ -298,22 +298,17 @@ func (m *manager) Set(container *configs.Config) error {
 
 // Freeze toggles the container's freezer cgroup depending on the state
 // provided
-func (m *manager) Freeze(state configs.FreezerState) (Err error) {
+func (m *manager) Freeze(state configs.FreezerState) error {
 	path := m.Path("freezer")
 	if m.cgroups == nil || path == "" {
 		return errors.New("cannot toggle freezer: cgroups not configured for container")
 	}
 
 	prevState := m.cgroups.Resources.Freezer
 	m.cgroups.Resources.Freezer = state
-	defer func() {
-		if Err != nil {
-			m.cgroups.Resources.Freezer = prevState
-		}
-	}()
-
 	freezer := &FreezerGroup{}
 	if err := freezer.Set(path, m.cgroups); err != nil {
+		m.cgroups.Resources.Freezer = prevState
 		return err
 	}
 	return nil