* nxos_facts: Remove dead code
The commit e51964e made this redundant as the structured case is handled
elsewhere.
* nxos_facts: Do not gather neighbors redundantly
LLDP reports the neighbor using the abbreviated interface name, whereas
CDP reports the neighbor using the full interface name. Normalize the
local interface name in the LLDP case, so there is no redundant
information. Due to the order of the gathering, CDP neighbors are saved
in case both LLDP and CDP data is available on a certain interface.
(cherry picked from commit 2019f0e430)