Remove no longer used uid/gid mapping functions

Now that all the user namespace code is moved into C, these routines are
no longer used.

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)

libcontainer/container_nouserns_linux.go

@@ -1,13 +0,0 @@
-// +build !go1.4
-
-package libcontainer
-
-import (
-	"fmt"
-	"syscall"
-)
-
-// not available before go 1.4
-func (c *linuxContainer) addUidGidMappings(sys *syscall.SysProcAttr) error {
-	return fmt.Errorf("User namespace is not supported in golang < 1.4")
-}

libcontainer/container_userns_linux.go

@@ -1,26 +0,0 @@
-// +build go1.4
-
-package libcontainer
-
-import "syscall"
-
-// Converts IDMap to SysProcIDMap array and adds it to SysProcAttr.
-func (c *linuxContainer) addUidGidMappings(sys *syscall.SysProcAttr) error {
-	if c.config.UidMappings != nil {
-		sys.UidMappings = make([]syscall.SysProcIDMap, len(c.config.UidMappings))
-		for i, um := range c.config.UidMappings {
-			sys.UidMappings[i].ContainerID = um.ContainerID
-			sys.UidMappings[i].HostID = um.HostID
-			sys.UidMappings[i].Size = um.Size
-		}
-	}
-	if c.config.GidMappings != nil {
-		sys.GidMappings = make([]syscall.SysProcIDMap, len(c.config.GidMappings))
-		for i, gm := range c.config.GidMappings {
-			sys.GidMappings[i].ContainerID = gm.ContainerID
-			sys.GidMappings[i].HostID = gm.HostID
-			sys.GidMappings[i].Size = gm.Size
-		}
-	}
-	return nil
-}