tests/setgroups.c: use errno2name
tests/setgroups.c: use errno2name

* tests/setgroups.c (errno2str): Remove.
(main): Use errno2name.

cuviper/strace,Saruta/strace,Saruta/strace,cuviper/strace,Saruta/strace,Saruta/strace,cuviper/strace,cuviper/strace,cuviper/strace,Saruta/strace