net: bridge: convert mtu_set_by_user to a bit

Convert the last remaining bool option to a bit thus reducing the overall
net_bridge size further by 8 bytes.
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_device.c

@@ -228,7 +228,7 @@ static int br_change_mtu(struct net_device *dev, int new_mtu)
 	dev->mtu = new_mtu;
 
 	/* this flag will be cleared if the MTU was automatically adjusted */
-	br->mtu_set_by_user = true;
+	br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 	/* remember the MTU in the rtable for PMTU */
 	dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);

net/bridge/br_if.c

@@ -508,14 +508,14 @@ void br_mtu_auto_adjust(struct net_bridge *br)
 	ASSERT_RTNL();
 
 	/* if the bridge MTU was manually configured don't mess with it */
-	if (br->mtu_set_by_user)
+	if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
 		return;
 
 	/* change to the minimum MTU and clear the flag which was set by
 	 * the bridge ndo_change_mtu callback
 	 */
 	dev_set_mtu(br->dev, br_mtu_min(br));
-	br->mtu_set_by_user = false;
+	br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
 }
 
 static void br_set_gso_limits(struct net_bridge *br)

net/bridge/br_private.h

@@ -319,6 +319,7 @@ enum net_bridge_opts {
 	BROPT_MULTICAST_STATS_ENABLED,
 	BROPT_HAS_IPV6_ADDR,
 	BROPT_NEIGH_SUPPRESS_ENABLED,
+	BROPT_MTU_SET_BY_USER,
 };
 
 struct net_bridge {
@@ -415,7 +416,6 @@ struct net_bridge {
 #ifdef CONFIG_NET_SWITCHDEV
 	int offload_fwd_mark;
 #endif
-	bool				mtu_set_by_user;
 	struct hlist_head		fdb_list;
 };