libcgroup Test: libcgroup-modify_cgroup-test3-for-multimnt

libcgroup Test: libcgroup-modify_cgroup-test3-for-multimnt

This patch adds a testcase for libcgroup api cgroup_modify_cgroup() for
commongroup (under two controllers) in multiple mount scenario.

Again the challenge is to handle the control value as diff controllers put diff
upper limit on control value and we pick the controller dynamicaly.
So thoughts ???

Signed-off-by: Sudhir Kumar <skumar@linux.vnet.ibm.com>
git-svn-id: https://libcg.svn.sourceforge.net/svnroot/libcg/trunk@264 4f4bb910-9a46-0410-90c8-c897d4f1cd53