lxc-ps: handle cgroup collisions

A few months ago cgroup handling in lxc was updated so that if
/sys/fs/cgroup/$cgroup/lxc/$container already exists (most often
due to another container by the same name under a different lxcpath),
then /sys/fs/cgroup/$cgroup/lxc/${container}-N would be used.

lxc-ps was never updated to handle this.  Fix that.

(Note, the ns cgroup is being special cased there, but I don't
really believe ns cgroup works any more.)

It would be preferable to rewrite lxc-ps in python or in C, but
this at least makes the basic lxc-ps work in the case of multiple
containers with the same name.

Changelog:
	fix missing fi.
	replace 'z1' with '$container' as pointed out by Christian

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
lxc-monitor multiple paths

Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>