Description of problem:

a customer was complaining about sss_cache returning 2, ENOENT ( no entries
invalidated in the cache ).

Or even think about the possibility of always returning 0 since "no entries
invalidated" is also successful.

German said he reproduced this easily:
Well, I have reproduced very easily like this:

=======================
[root@ipatrust ~]# rm -rf /var/lib/sss/db/* 

[root@ipatrust ~]# systemctl restart sssd.service

[root@ipatrust ~]# sss_cache -G
No cache object matched the specified search

[root@ipatrust ~]# echo $?
2


[root@ipatrust ~]# sss_cache -U
No cache object matched the specified search

[root@ipatrust ~]# echo $?
2

This seems to be expected return "no entries" when there's nothing to invalidate.

Now:

[root@ipatrust ~]# id gparente
uid=142600006(gparente) gid=142600006(gparente) groups=142600006(gparente),142600015(newgroup)

[root@ipatrust ~]# sss_cache -U
[root@ipatrust ~]# echo $?
0