There are several cases:
 * we run the lxc-create as root, the @path@/var/lib/lxc will be created
 * we run the lxc-create as non-root, the creation of the directory will
   fail with "permission denied", so we should call lxc-setcap before
 * we run lxc-setcap (always as root), we create the directory and set
   the permission for everyone.
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>