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/multicast.c b/drivers/infiniband/core/multicast.c
index b57ed03..605f20a 100644
--- a/drivers/infiniband/core/multicast.c
+++ b/drivers/infiniband/core/multicast.c
@@ -780,7 +780,7 @@
 	int index;
 
 	dev = container_of(handler, struct mcast_device, event_handler);
-	if (WARN_ON(!rdma_protocol_ib(dev->device, event->element.port_num)))
+	if (WARN_ON(!rdma_cap_ib_mcast(dev->device, event->element.port_num)))
 		return;
 
 	index = event->element.port_num - dev->start_port;
@@ -820,7 +820,7 @@
 	}
 
 	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
-		if (!rdma_protocol_ib(device, dev->start_port + i))
+		if (!rdma_cap_ib_mcast(device, dev->start_port + i))
 			continue;
 		port = &dev->port[i];
 		port->dev = dev;
@@ -858,7 +858,7 @@
 	flush_workqueue(mcast_wq);
 
 	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
-		if (rdma_protocol_ib(device, dev->start_port + i)) {
+		if (rdma_cap_ib_mcast(device, dev->start_port + i)) {
 			port = &dev->port[i];
 			deref_port(port);
 			wait_for_completion(&port->comp);