Remove unused runc files

We no longer use runc code to read network I/O usage. This lets
us remove a lot of vendored code.

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

Closes: #425
Approved by: rhatdan

vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs/freezer.go

@@ -1,66 +0,0 @@
-// +build linux
-
-package fs
-
-import (
-	"fmt"
-	"strings"
-	"time"
-
-	"github.com/opencontainers/runc/libcontainer/cgroups"
-	"github.com/opencontainers/runc/libcontainer/configs"
-)
-
-type FreezerGroup struct {
-}
-
-func (s *FreezerGroup) Name() string {
-	return "freezer"
-}
-
-func (s *FreezerGroup) Apply(d *cgroupData) error {
-	_, err := d.join("freezer")
-	if err != nil && !cgroups.IsNotFound(err) {
-		return err
-	}
-	return nil
-}
-
-func (s *FreezerGroup) Set(path string, cgroup *configs.Cgroup) error {
-	switch cgroup.Resources.Freezer {
-	case configs.Frozen, configs.Thawed:
-		for {
-			// In case this loop does not exit because it doesn't get the expected
-			// state, let's write again this state, hoping it's going to be properly
-			// set this time. Otherwise, this loop could run infinitely, waiting for
-			// a state change that would never happen.
-			if err := writeFile(path, "freezer.state", string(cgroup.Resources.Freezer)); err != nil {
-				return err
-			}
-
-			state, err := readFile(path, "freezer.state")
-			if err != nil {
-				return err
-			}
-			if strings.TrimSpace(state) == string(cgroup.Resources.Freezer) {
-				break
-			}
-
-			time.Sleep(1 * time.Millisecond)
-		}
-	case configs.Undefined:
-		return nil
-	default:
-		return fmt.Errorf("Invalid argument '%s' to freezer.state", string(cgroup.Resources.Freezer))
-	}
-
-	return nil
-}
-
-func (s *FreezerGroup) Remove(d *cgroupData) error {
-	return removePath(d.path("freezer"))
-}
-
-func (s *FreezerGroup) GetStats(path string, stats *cgroups.Stats) error {
-	return nil
-}