IB/mlx5: Fix the locking of SRQ objects in ODP events

QP and SRQ objects are stored in different containers so the action to get
and lock a common resource during ODP event needs to address that.

While here get rid of 'refcount' and 'free' fields in mlx5_core_srq struct
and use the fields with same semantics in common structure.

Fixes: 032080ab43 ("IB/mlx5: Lock QP during page fault handling")
Signed-off-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/cq.c

@@ -187,8 +187,8 @@ static void handle_responder(struct ib_wc *wc, struct mlx5_cqe64 *cqe,
 			wqe_ctr = be16_to_cpu(cqe->wqe_counter);
 			wc->wr_id = srq->wrid[wqe_ctr];
 			mlx5_ib_free_srq_wqe(srq, wqe_ctr);
-			if (msrq && atomic_dec_and_test(&msrq->refcount))
-				complete(&msrq->free);
+			if (msrq)
+				mlx5_core_res_put(&msrq->common);
 		}
 	} else {
 		wq	  = &qp->rq;