cgconfig: add err check
cgconfig: add err check

cgroup still can be created even if giving invalid -d,-f,-s parameter.
e.g.
        cgconfigparser  -d 888 -l /etc/cgconfig.conf
        "888" is invalid, but cgroup will be created.

        So we should exit when -d,-f or -s is invalid.

v3:
 - add nonzero return value
 - use error instead of ret

Signed-off-by: Libo Chen <3ddb76ce901f50183fdff8d1ff6862f91b38880c@huawei.com>
Acked-by: Ivana Hutarova Varekova <2e3918a0a366ea7e658a2062ab582c898a7e1b1b@redhat.com>

rafalmiel/libcg,rafalmiel/libcg,rafalmiel/libcg,rafalmiel/libcg