rsockets: Use wr_id to determine completion type

rsockets: Use wr_id to determine completion type

If a work request has completed in error, the completion type
field is undefined.  Use the wr_id to determine if the failed
completion was a send or receive.

This fixes an issue where MPI can hang during finalize.  With
both sides of a connection shutting down simultaneously, one
side may complete quicker and delete its QP before the other
side receives an acknowledgement to their disconnect message.
Eventually, the disconnect message will time out, but because
the completion type field is undefined, it may be processed
as a failed receive, rather than a failed send.  The end
result is that the second side hangs waiting for the send to
complete.

This problem showed up more easily after commit
2e5b0fc95964f74ea59dd725e849027faa0cd526, but existed beforehand.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>