tools/cgxget: fix the resource leak in convert_cgroup()

tools/cgxget: fix the resource leak in convert_cgroup()

Fix a resource leak warning reported by the Coverity tool:

CID 258272 (#1-2 of 2): Resource leak (RESOURCE_LEAK). leaked_storage:
Variable cg_converted_list going out of scope leaks the storage it
points to.

while free'ing() the cg_converted_list() via cgroup_free(), wrong array
index variable was passed, causing the resource leak. Fix it by passing
the right index variable.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>