bgpd: fix resolvedPrefix in show nexthop json output

bgpd: fix resolvedPrefix in show nexthop json output

While populating  the nexthop info for "show bgp nexthop json", resolvedPrefix
is added in parent json object instead of json_nexthop object.
This results in displaying wrong resolvedPrefix for nexthops.
Fixing the same by adding resolvedPrefix to json_nexthop object, so that
the proper resolvedPrefix would be displayed for the respective nexthop

Signed-off-by: Krishnasamy R <krishnasamyr@nvidia.com>
(cherry picked from commit 95c08e082c063374cbc62dea6529c8f54b0722df)