ospfd: Memory Leak seen at show_ip_ospf_neighbor_all_common.

ospfd: Memory Leak seen at show_ip_ospf_neighbor_all_common.

Problem Statement:
==================
Memory Leak seen at  show_ip_ospf_neighbor_all_common (ospf_vty.c:4635)

RCA:
=================
In function show_ip_ospf_neighbor_all_common, one child json object is not
 added to the parent child object when there is no nbma neighbor. Hence
 the memory leak.

Fix:
=================
Add the child object to the parent json object.

Fixes: #9548
Signed-off-by: Mobashshera Rasool <mrasool@vmware.com>