Remove redundant list_router_interfaces()

list_router_interfaces() just passes router_id as a filter to
"list ports" API on Neutron. So it is easy to implement the metod
with list_ports() instead.
This patch removes the redundant method and makes it use list_ports().

Partially implements blueprint consistent-service-method-names

Change-Id: I32d4fab72df8786982d02960770c97e698e34ce3
4 files changed