IB/mad: use CQ abstraction

Remove the local workqueue to process mad completions and use the CQ API
instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hal Rosenstock <hal@mellanox.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/mad_priv.h

@@ -64,6 +64,7 @@
 
 struct ib_mad_list_head {
 	struct list_head list;
+	struct ib_cqe cqe;
 	struct ib_mad_queue *mad_queue;
 };
 
@@ -204,7 +205,6 @@ struct ib_mad_port_private {
 	struct ib_mad_mgmt_version_table version[MAX_MGMT_VERSION];
 	struct list_head agent_list;
 	struct workqueue_struct *wq;
-	struct work_struct work;
 	struct ib_mad_qp_info qp_info[IB_MAD_QPS_CORE];
 };