tipc: Add monitoring of number of nodes discovered by bearer

Augments TIPC's discovery object to track the number of neighboring nodes
having an active link to the associated bearer.

This means tipc_disc_update_link_req() becomes either one of:

       tipc_disc_add_dest()
or:
       tipc_disc_remove_dest()

depending on the code flow direction of things.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 5fcd1c1..85209ea 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -344,15 +344,15 @@
 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
 {
 	tipc_nmap_add(&b_ptr->nodes, dest);
-	tipc_disc_update_link_req(b_ptr->link_req);
 	tipc_bcbearer_sort();
+	tipc_disc_add_dest(b_ptr->link_req);
 }
 
 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
 {
 	tipc_nmap_remove(&b_ptr->nodes, dest);
-	tipc_disc_update_link_req(b_ptr->link_req);
 	tipc_bcbearer_sort();
+	tipc_disc_remove_dest(b_ptr->link_req);
 }
 
 /*