Bump Libcontainer to latest head

vendor/github.com/opencontainers/runc/libcontainer/selinux/selinux.go

@@ -16,7 +16,6 @@ import (
 	"sync"
 	"syscall"
 
-	"github.com/docker/docker/pkg/mount"
 	"github.com/opencontainers/runc/libcontainer/system"
 )
 
@@ -60,16 +59,31 @@ func getSelinuxMountPoint() string {
 	}
 	selinuxfs = ""
 
-	mounts, err := mount.GetMounts()
+	f, err := os.Open("/proc/self/mountinfo")
 	if err != nil {
 		return selinuxfs
 	}
-	for _, mount := range mounts {
-		if mount.Fstype == "selinuxfs" {
-			selinuxfs = mount.Mountpoint
-			break
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		txt := scanner.Text()
+		// Safe as mountinfo encodes mountpoints with spaces as \040.
+		sepIdx := strings.Index(txt, " - ")
+		if sepIdx == -1 {
+			continue
 		}
+		if !strings.Contains(txt[sepIdx:], "selinuxfs") {
+			continue
+		}
+		fields := strings.Split(txt, " ")
+		if len(fields) < 5 {
+			continue
+		}
+		selinuxfs = fields[4]
+		break
 	}
+
 	if selinuxfs != "" {
 		var buf syscall.Statfs_t
 		syscall.Statfs(selinuxfs, &buf)
@@ -297,7 +311,7 @@ func IntToMcs(id int, catRange uint32) string {
 
 	for ORD > TIER {
 		ORD = ORD - TIER
-		TIER -= 1
+		TIER--
 	}
 	TIER = SETSIZE - TIER
 	ORD = ORD + TIER
@@ -438,7 +452,7 @@ func badPrefix(fpath string) error {
 	return nil
 }
 
-// Change the fpath file object to the SELinux label scon.
+// Chcon changes the fpath file object to the SELinux label scon.
 // If the fpath is a directory and recurse is true Chcon will walk the
 // directory tree setting the label
 func Chcon(fpath string, scon string, recurse bool) error {
@@ -472,14 +486,14 @@ func DupSecOpt(src string) []string {
 		con["level"] == "" {
 		return nil
 	}
-	return []string{"label:user:" + con["user"],
-		"label:role:" + con["role"],
-		"label:type:" + con["type"],
-		"label:level:" + con["level"]}
+	return []string{"label=user:" + con["user"],
+		"label=role:" + con["role"],
+		"label=type:" + con["type"],
+		"label=level:" + con["level"]}
 }
 
 // DisableSecOpt returns a security opt that can be used to disabling SELinux
 // labeling support for future container processes
 func DisableSecOpt() []string {
-	return []string{"label:disable"}
+	return []string{"label=disable"}
 }