dcb: data center bridging ops should be r/o

The data center bridging ops structure can be const

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 94958c1..b332eef 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -909,7 +909,7 @@
 
 #ifdef CONFIG_DCB
 	/* Data Center Bridging netlink ops */
-	struct dcbnl_rtnl_ops *dcbnl_ops;
+	const struct dcbnl_rtnl_ops *dcbnl_ops;
 #endif
 
 #if defined(CONFIG_FCOE) || defined(CONFIG_FCOE_MODULE)