LDAP: unlink ccname_file_dummy if there is an error
https://fedorahosted.org/sssd/ticket/2592
If there is an error after ccname_file_dummy is created but before it is
renamed then the file isn't removed. This can cause a lot of files to be
created and take up inodes in a filesystem.
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
Reviewed-by: Sumit Bose <sbose@redhat.com>
(cherry picked from commit 2b20ff2e33ad3993a9cad910c4b4b828513613df)