net: dsa: Fix OF fallback lookup for ports

The variable 'node' was already invalid, so using it for further
lookup will not work.

Signed-off-by: Marcus Comstedt <marcus.comstedt@requtech.se>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/net/dsa-uclass.c b/net/dsa-uclass.c
index dd78e57..f64c68e 100644
--- a/net/dsa-uclass.c
+++ b/net/dsa-uclass.c
@@ -381,7 +381,7 @@
 
 	node = ofnode_find_subnode(node, "ports");
 	if (!ofnode_valid(node))
-		node = ofnode_find_subnode(node, "ethernet-ports");
+		node = ofnode_find_subnode(dev_ofnode(dev), "ethernet-ports");
 	if (!ofnode_valid(node)) {
 		dev_err(dev, "ports node is missing under DSA device!\n");
 		return -EINVAL;