XR 7+: get_lldp_neighbors_detail query only the NodeTable

[mirceaulinic]

It looks like in newer XR systems, just querying LLDP at the top level
throws this error:

xml-schema[oper]:> walkdata LLDP
%MGBL-SCHBRO-7-GET : [xml-schema] While fetching object LLDP.GlobalLLDP.LLDPInfo the following error occurred:
Invalid argument

And over the XML mode:

XML> <?xml version="1.0" encoding="UTF-8"?><Request MajorVersion="1" MinorVersion="0"><Get><Operational><LLDP></LLDP></Operational></Get></Request>
<?xml version="1.0" encoding="UTF-8"?>
<Response MajorVersion="1" MinorVersion="0">
    <Get ErrorCode="0x43679000" ErrorMsg="&apos;XML Service Library&apos; detected the &apos;warning&apos; condition &apos;An error was encountered in the XML beneath this operation tag&apos;" ItemNotFound="true">
        <Operational>
            <LLDP MajorVersion="1" MinorVersion="1">
                <GlobalLLDP>
                    <LLDPInfo ErrorCode="0x16" ErrorMsg="Invalid argument"/>
                </GlobalLLDP>
            </LLDP>
        </Operational>
    </Get>
    <ResultSummary ErrorCount="1"/>
</Response>

Re-scoping the request to gather explicitly the NodeTable not only that
reduces the reply whenever there's more available under the LLDP
operational level, but also prevents us from bumping into this error,
while returning the neighbours as required.

[ktbyers]

LGTM