The cgroup mounts created by cgroup-bin do not show up in /etc/mtab.
lxc-ls, as lxc-ps before it, assumes that /etc/mtab is symlinked to
/proc/mounts.
Author: Serge Hallyn <serge.hallyn@canonical.com>
Forwarded: no
Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/819319Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>