RDMA/cma: Optimize cma_bind_loopback() to check for empty list

Optimize to test for an empty list first.  This ends up simplifying
the code too.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/cma.c

@@ -1481,19 +1481,18 @@ static int cma_bind_loopback(struct rdma_id_private *id_priv)
 	u8 p;
 
 	mutex_lock(&lock);
+	if (list_empty(&dev_list)) {
+		ret = -ENODEV;
+		goto out;
+	}
 	list_for_each_entry(cma_dev, &dev_list, list)
 		for (p = 1; p <= cma_dev->device->phys_port_cnt; ++p)
-			if (!ib_query_port (cma_dev->device, p, &port_attr) &&
+			if (!ib_query_port(cma_dev->device, p, &port_attr) &&
 			    port_attr.state == IB_PORT_ACTIVE)
 				goto port_found;
 
-	if (!list_empty(&dev_list)) {
 	p = 1;
 	cma_dev = list_entry(dev_list.next, struct cma_device, list);
-	} else {
-		ret = -ENODEV;
-		goto out;
-	}
 
 port_found:
 	ret = ib_get_cached_gid(cma_dev->device, p, 0, &gid);