RDMA/nes: Report correct port state if interface is down

With commit cd6860eb ("RDMA/nes: Fix hangs on ifdown") we no longer
remove nes interfaces on ifdown.  On nes_query_port(), add an
additional check of the netdev queue and report IB_PORT_DOWN if the
queue is not running.

Signed-off-by: Chien Tung <chien.tin.tung@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>