IB/Verbs: Use management helper rdma_cap_ib_smi()

Introduce helper rdma_cap_ib_smi() to help us check if the port of an
IB device support Infiniband Subnet Management Interface.

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/agent.c b/drivers/infiniband/core/agent.c
index 89d4fbc..a6fc4d6 100644
--- a/drivers/infiniband/core/agent.c
+++ b/drivers/infiniband/core/agent.c
@@ -156,7 +156,7 @@
 		goto error1;
 	}
 
-	if (rdma_protocol_ib(device, port_num)) {
+	if (rdma_cap_ib_smi(device, port_num)) {
 		/* Obtain send only MAD agent for SMI QP */
 		port_priv->agent[0] = ib_register_mad_agent(device, port_num,
 							    IB_QPT_SMI, NULL, 0,