lscgroup: polish usage function
lscgroup: polish usage function

This change is suggested by Dhaval Giani <f48451d72a1ad74c777093928b661ad7099a85df@gmail.com>.
Polish "usage" function of lscgroup tool. Remove a level of indentation.

Signed-off-by: Ivana Hutarova Varekova <2e3918a0a366ea7e658a2062ab582c898a7e1b1b@redhat.com>
Acked-by: Dhaval Giani <f48451d72a1ad74c777093928b661ad7099a85df@gmail.com>
Acked-by: Jan Safranek <a7f4b96ffdd515ecef00f117294da18555749b0b@redhat.com>

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