OTP: emit a log message when LDAP entry for config record is not found
    
    This patch proposes a fix to the following defect found by covscan of FreeIPA
    master code:
    
    """
    Error: CHECKED_RETURN (CWE-252):
    /daemons/ipa-slapi-plugins/libotp/otp_config.c:239: check_return: Calling
    "slapi_search_internal_get_entry" without checking return value (as is done
    elsewhere 14 out of 16 times).
    /daemons/ipa-slapi-plugins/ipa-enrollment/ipa_enrollment.c:402:
    example_checked: Example 1: "slapi_search_internal_get_entry(sdn, NULL,
    &config_entry, ipaenrollment_plugin_id)" has its value checked in "(rc =
    slapi_search_internal_get_entry(sdn, NULL, &config_entry,
    ipaenrollment_plugin_id)) != 0".
    /daemons/ipa-slapi-plugins/ipa-lockout/ipa_lockout.c:207: example_assign:
    Example 2: Assigning: "ret" = return value from
    "slapi_search_internal_get_entry(sdn, NULL, &config_entry, getPluginID())".
    /daemons/ipa-slapi-plugins/ipa-lockout/ipa_lockout.c:212: example_checked:
    Example 2 (cont.): "ret" has its value checked in "ret".
    /daemons/ipa-slapi-plugins/ipa-pwd-extop/common.c:651: example_assign: Example
    3: Assigning: "search_result" = return value from
    "slapi_search_internal_get_entry(sdn, attrlist, e2, ipapwd_plugin_id)".
    /daemons/ipa-slapi-plugins/ipa-pwd-extop/common.c:653: example_checked:
    Example 3 (cont.): "search_result" has its value checked in "search_result !=
    0".  /daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c:1035: example_assign:
    Example 4: Assigning: "ret" = return value from
    "slapi_search_internal_get_entry(tmp_dn, NULL, &pwdop->pwdata.target,
    ipapwd_plugin_id)".
    /daemons/ipa-slapi-plugins/ipa-pwd-extop/prepost.c:1039:
    example_checked: Example 4 (cont.): "ret" has its value checked in "ret != 0".
    /daemons/ipa-slapi-plugins/ipa-uuid/ipa_uuid.c:817: example_assign: Example 5:
    Assigning: "ret" = return value from "slapi_search_internal_get_entry(tmp_dn,
    NULL, &e, getPluginID())".
    /daemons/ipa-slapi-plugins/ipa-uuid/ipa_uuid.c:820: example_checked: Example 5
    (cont.): "ret" has its value checked in "ret == 10".
    """
    
    The patch is a part of series related to
    https://fedorahosted.org/freeipa/ticket/4795
    
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>