tipc: introduce jumbo frame support for broadcast

Until now, we have only been supporting a fix MTU size of 1500 bytes
for all broadcast media, irrespective of their actual capability.

We now make the broadcast MTU adaptable to the carrying media, i.e.,
we use the smallest MTU supported by any of the interfaces attached
to TIPC.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/bcast.h b/net/tipc/bcast.h
index 76b747a..0cc7220 100644
--- a/net/tipc/bcast.h
+++ b/net/tipc/bcast.h
@@ -63,7 +63,7 @@
 			u32 node, bool action);
 int  tipc_bclink_reset_stats(struct net *net);
 int  tipc_bclink_set_queue_limits(struct net *net, u32 limit);
-uint  tipc_bcast_get_mtu(void);
+int  tipc_bcast_get_mtu(struct net *net);
 int tipc_bcast_xmit(struct net *net, struct sk_buff_head *list);
 int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb);
 void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l, u32 acked);