RDMA/ocrdma: Avoid reporting wrong completions in case of error CQEs

During cable pull test with a mount over NFS/RDMA, the driver was
reporting error completions when there were no pending requests in the
SQ and RQ.  This was triggering a host crash because of reporting
wrong work req id.  Avoid this crash by adding a check for SQ and RQ
empty condition and prevent reporting completions if queues are empty.

Signed-off-by: Selvin Xavier <selvin.xavier@emulex.com>
Signed-off-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>