net: dsa: use ports list to find a port by node

Use the new ports list instead of iterating over switches and their
ports to find a port from a given node.
Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

net/dsa/dsa2.c

@@ -113,22 +113,11 @@ static bool dsa_port_is_user(struct dsa_port *dp)
 static struct dsa_port *dsa_tree_find_port_by_node(struct dsa_switch_tree *dst,
 						   struct device_node *dn)
 {
-	struct dsa_switch *ds;
 	struct dsa_port *dp;
-	int device, port;
-
-	for (device = 0; device < DSA_MAX_SWITCHES; device++) {
-		ds = dst->ds[device];
-		if (!ds)
-			continue;
 
-		for (port = 0; port < ds->num_ports; port++) {
-			dp = &ds->ports[port];
-
-			if (dp->dn == dn)
-				return dp;
-		}
-	}
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dp->dn == dn)
+			return dp;
 
 	return NULL;
 }