p11_child: add descriptions for error codes to debug messages
Additionally to the NSS erro code a text message describing the error is
added. This will help to see why p11_child ignores specific
certificates. For example it would be more obvious why the certificate
is not valid (expired, missing CA cert, failed OCSP etc).
Related to https://pagure.io/SSSD/sssd/issue/3560
Reviewed-by: Fabiano FidĂȘncio <fidencio@redhat.com>
Tested-by: Scott Poore <spoore@redhat.com>