attempt_refresh_cred
err = attempt_refresh_cred(kmd, user, PAM_REINITIALIZE_CRED);
err = attempt_refresh_cred(kmd, user, PAM_REFRESH_CRED);
err = attempt_refresh_cred(kmd, user, PAM_ESTABLISH_CRED);
static int attempt_refresh_cred(krb5_module_data_t *, const char *, int);