bridge: netlink: account for the IFLA_BRPORT_PROXYARP_WIFI attribute size and policy

The attribute size wasn't accounted for in the get_slave_size() callback
(br_port_get_slave_size) when it was introduced, so fix it now. Also add
a policy entry for it in br_port_policy.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Fixes: 842a9ae08a25 ("bridge: Extend Proxy ARP design to allow optional rules for Wi-Fi")
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 5390536..4d74a06 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -113,6 +113,7 @@
 		+ nla_total_size(1)	/* IFLA_BRPORT_LEARNING */
 		+ nla_total_size(1)	/* IFLA_BRPORT_UNICAST_FLOOD */
 		+ nla_total_size(1)	/* IFLA_BRPORT_PROXYARP */
+		+ nla_total_size(1)	/* IFLA_BRPORT_PROXYARP_WIFI */
 		+ 0;
 }
 
@@ -508,6 +509,7 @@
 	[IFLA_BRPORT_LEARNING]	= { .type = NLA_U8 },
 	[IFLA_BRPORT_UNICAST_FLOOD] = { .type = NLA_U8 },
 	[IFLA_BRPORT_PROXYARP]	= { .type = NLA_U8 },
+	[IFLA_BRPORT_PROXYARP_WIFI] = { .type = NLA_U8 },
 };
 
 /* Change the state of the port and notify spanning tree */