tipc: Add routines for safe checking of node's network address

Introduces routines that test whether a given network address is
equal to a node's own network address or if it lies within the node's
own network cluster, and which work properly regardless of whether
the node is using the default network address <0.0.0> or a non-zero
network address that is assigned later on. In essence, these routines
ensure that address <0.0.0> is treated as an alias for "this node",
regardless of which network address the node is actually using.

Old users of the pre-existing more strict match in_own_cluster()
have been accordingly redirected to what is now called
in_own_cluster_exact() --- which does not extend matching to <0,0,0>.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/tipc/node.c b/net/tipc/node.c
index a34cabc..6a71bea 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -72,7 +72,7 @@
 	struct tipc_node *node;
 	struct hlist_node *pos;
 
-	if (unlikely(!in_own_cluster(addr)))
+	if (unlikely(!in_own_cluster_exact(addr)))
 		return NULL;
 
 	hlist_for_each_entry(node, pos, &node_htable[tipc_hashfn(addr)], hash) {