IB/qib: Unnecessary delayed completions on RC connection

Currently on receipt of a response message (ACKs, RDMA Response,
Atomic Responses etc.) if the SDMA completion counter is not advanced
the driver delays the completion of the WQE.  In most cases this is
overly pessimistic as the response (ACK) to a previously transmitted
send implies that the send is complete.  Ensure that SDMA queue is
progressed appropriately before determining if a send has delayed
completions.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>