Setting lxc.console = none causes startup failures for the containers that runs in user namespace

Setting "lxc.console = none" causes following failure during startup

      lxc-start 1389039861.061 INFO     lxc_start_ui - using rcfile lxcpath/original/config
      lxc-start 1389039861.062 INFO     lxc_confile - read uid map: type u nsid 0 hostid 260000 range 10000
      lxc-start 1389039861.062 INFO     lxc_confile - read uid map: type g nsid 0 hostid 260000 range 10000
      lxc-start 1389039861.062 WARN     lxc_log - lxc_log_init called with log already initialized
      lxc-start 1389039861.065 INFO     lxc_lsm - LSM security driver AppArmor
      lxc-start 1389039861.066 DEBUG    lxc_conf - allocated pty '/dev/pts/0' (5/6)
      lxc-start 1389039861.066 DEBUG    lxc_conf - allocated pty '/dev/pts/7' (7/8)
      lxc-start 1389039861.066 DEBUG    lxc_conf - allocated pty '/dev/pts/8' (9/10)
      lxc-start 1389039861.066 DEBUG    lxc_conf - allocated pty '/dev/pts/9' (11/12)
      lxc-start 1389039861.066 INFO     lxc_conf - tty's configured
      lxc-start 1389039861.066 DEBUG    lxc_start - sigchild handler set
      lxc-start 1389039861.066 ERROR    lxc_conf - Error chowning
      lxc-start 1389039861.066 ERROR    lxc_conf - Failed to chown
      lxc-start 1389039861.066 ERROR    lxc_start - Failed to shift tty into container
      lxc-start 1389039861.066 ERROR    lxc_start - failed to initialize the container
      lxc-start 1389039861.067 INFO     lxc_monitor - using monitor sock name lxc/0863ffed81827105/lxcpath

fix it by checking the console.name before using it.

Signed-off-by: S.Çağlar Onur <caglar@10ur.org>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>