RDMA/efa: Remove redundant NULL pointer check of CQE

RDMA/efa: Remove redundant NULL pointer check of CQE

A pointer to store the command completion must be provided as it is always
used in efa_com_put_comp_ctx() to return the completion context back to
the pool. Remove the NULL pointer check and the redundant 'status' field
stored on the context as it could be retrieved from the completion itself.

Link: https://lore.kernel.org/r/20210126120702.9807-2-galpress@amazon.com
Reviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>