libcgroup: free global config_cgroup_table
libcgroup: free global config_cgroup_table

To be able to call the cgroup_parse_config() several times without memory
leaks, its callers should free the memory it allocates when they don't need
it.

Signed-off-by: Jan Safranek <a7f4b96ffdd515ecef00f117294da18555749b0b@redhat.com>

rafalmiel/libcg,jrfastab/Linux-cgdcbxd,jrfastab/Linux-cgdcbxd,rafalmiel/libcg,jrfastab/Linux-cgdcbxd,rafalmiel/libcg,rafalmiel/libcg,jrfastab/Linux-cgdcbxd