IB/Verbs: Use management helper rdma_cap_ib_mcast()

Introduce helper rdma_cap_ib_mcast() to help us check if the port of an
IB device support Infiniband Multicast.

Signed-off-by: Michael Wang <yun.wang@profitbricks.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 6d65460..78becc7 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -1014,7 +1014,7 @@
 		mc = container_of(id_priv->mc_list.next,
 				  struct cma_multicast, list);
 		list_del(&mc->list);
-		if (rdma_protocol_ib(id_priv->cma_dev->device,
+		if (rdma_cap_ib_mcast(id_priv->cma_dev->device,
 				      id_priv->id.port_num)) {
 			ib_sa_free_multicast(mc->multicast.ib);
 			kfree(mc);
@@ -3328,7 +3328,7 @@
 	if (rdma_protocol_iboe(id->device, id->port_num)) {
 		kref_init(&mc->mcref);
 		ret = cma_iboe_join_multicast(id_priv, mc);
-	} else if (rdma_protocol_ib(id->device, id->port_num))
+	} else if (rdma_cap_ib_mcast(id->device, id->port_num))
 		ret = cma_join_ib_multicast(id_priv, mc);
 	else
 		ret = -ENOSYS;
@@ -3362,7 +3362,7 @@
 
 			BUG_ON(id_priv->cma_dev->device != id->device);
 
-			if (rdma_protocol_ib(id->device, id->port_num)) {
+			if (rdma_cap_ib_mcast(id->device, id->port_num)) {
 				ib_sa_free_multicast(mc->multicast.ib);
 				kfree(mc);
 			} else if (rdma_protocol_iboe(id->device, id->port_num))