RDMA/nes: FIN during MPA startup causes timeout

A FIN that is received during an MPA start up sequence causes a
timeout in iwcm.c.  The connection has not been completely closed so
the iwcm code is waiting for resources to be cleaned up.  This closes
the connection so everything cleans up correctly.

Signed-off-by: Don Wood <donald.e.wood@intel.com>
Signed-off-by: Faisal Latif <faisal.latif@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>