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/hugetlb.go

@@ -1,71 +0,0 @@
-// +build linux
-
-package fs
-
-import (
-	"fmt"
-	"strconv"
-	"strings"
-
-	"github.com/opencontainers/runc/libcontainer/cgroups"
-	"github.com/opencontainers/runc/libcontainer/configs"
-)
-
-type HugetlbGroup struct {
-}
-
-func (s *HugetlbGroup) Name() string {
-	return "hugetlb"
-}
-
-func (s *HugetlbGroup) Apply(d *cgroupData) error {
-	_, err := d.join("hugetlb")
-	if err != nil && !cgroups.IsNotFound(err) {
-		return err
-	}
-	return nil
-}
-
-func (s *HugetlbGroup) Set(path string, cgroup *configs.Cgroup) error {
-	for _, hugetlb := range cgroup.Resources.HugetlbLimit {
-		if err := writeFile(path, strings.Join([]string{"hugetlb", hugetlb.Pagesize, "limit_in_bytes"}, "."), strconv.FormatUint(hugetlb.Limit, 10)); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func (s *HugetlbGroup) Remove(d *cgroupData) error {
-	return removePath(d.path("hugetlb"))
-}
-
-func (s *HugetlbGroup) GetStats(path string, stats *cgroups.Stats) error {
-	hugetlbStats := cgroups.HugetlbStats{}
-	for _, pageSize := range HugePageSizes {
-		usage := strings.Join([]string{"hugetlb", pageSize, "usage_in_bytes"}, ".")
-		value, err := getCgroupParamUint(path, usage)
-		if err != nil {
-			return fmt.Errorf("failed to parse %s - %v", usage, err)
-		}
-		hugetlbStats.Usage = value
-
-		maxUsage := strings.Join([]string{"hugetlb", pageSize, "max_usage_in_bytes"}, ".")
-		value, err = getCgroupParamUint(path, maxUsage)
-		if err != nil {
-			return fmt.Errorf("failed to parse %s - %v", maxUsage, err)
-		}
-		hugetlbStats.MaxUsage = value
-
-		failcnt := strings.Join([]string{"hugetlb", pageSize, "failcnt"}, ".")
-		value, err = getCgroupParamUint(path, failcnt)
-		if err != nil {
-			return fmt.Errorf("failed to parse %s - %v", failcnt, err)
-		}
-		hugetlbStats.Failcnt = value
-
-		stats.HugetlbStats[pageSize] = hugetlbStats
-	}
-
-	return nil
-}