update vendor

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

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

@@ -0,0 +1,23 @@
+package mount
+
+// GetMounts retrieves a list of mounts for the current running process.
+func GetMounts() ([]*Info, error) {
+	return parseMountTable()
+}
+
+// Mounted looks at /proc/self/mountinfo to determine of the specified
+// mountpoint has been mounted
+func Mounted(mountpoint string) (bool, error) {
+	entries, err := parseMountTable()
+	if err != nil {
+		return false, err
+	}
+
+	// Search the table for the mountpoint
+	for _, e := range entries {
+		if e.Mountpoint == mountpoint {
+			return true, nil
+		}
+	}
+	return false, nil
+}