net: bridge: add bitfield for options and convert vlan opts

Bridge options have usually been added as separate fields all over the
net_bridge struct taking up space and ending up in different cache lines.
Let's move them to a single bitfield to save up space and speedup lookups.
This patch adds a simple API for option modifying and retrieving using
bitops and converts the first user of the API - the bridge vlan options
(vlan_enabled and vlan_stats_enabled).

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_sysfs_br.c

@@ -743,7 +743,7 @@ static ssize_t vlan_filtering_show(struct device *d,
 				   char *buf)
 {
 	struct net_bridge *br = to_bridge(d);
-	return sprintf(buf, "%d\n", br->vlan_enabled);
+	return sprintf(buf, "%d\n", br_opt_get(br, BROPT_VLAN_ENABLED));
 }
 
 static ssize_t vlan_filtering_store(struct device *d,
@@ -791,7 +791,7 @@ static ssize_t vlan_stats_enabled_show(struct device *d,
 				       char *buf)
 {
 	struct net_bridge *br = to_bridge(d);
-	return sprintf(buf, "%u\n", br->vlan_stats_enabled);
+	return sprintf(buf, "%u\n", br_opt_get(br, BROPT_VLAN_STATS_ENABLED));
 }
 
 static ssize_t vlan_stats_enabled_store(struct device *d,