RDS: update rds-info related functions to traverse multiple conn_paths

This commit updates the callbacks related to the rds-info command
so that they walk through all the rds_conn_path structures and
report the requested info.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>