net: bridge: use netif_is_bridge_port()

Replace the br_port_exists() macro with its twin from netdevice.h

CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 9c07591..4f9f59e 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -102,7 +102,7 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
 	size_t vinfo_sz = 0;
 
 	rcu_read_lock();
-	if (br_port_exists(dev)) {
+	if (netif_is_bridge_port(dev)) {
 		p = br_port_get_rcu(dev);
 		vg = nbp_vlan_group_rcu(p);
 	} else if (dev->priv_flags & IFF_EBRIDGE) {