net: dsa: Fix an error handling path in 'dsa_switch_parse_ports_of()'

If we return before the end of the 'for_each_child_of_node()' iterator, the
reference taken on 'port' must be released.

Add the missing 'of_node_put()' calls.

Fixes: 83c0afae ("net: dsa: Add new binding implementation")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/15d5310d1d55ad51c1af80775865306d92432e03.1634587046.git.christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/dsa/dsa2.c

@@ -1374,12 +1374,15 @@ static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
 
 	for_each_available_child_of_node(ports, port) {
 		err = of_property_read_u32(port, "reg", &reg);
-		if (err)
+		if (err) {
+			of_node_put(port);
 			goto out_put_node;
+		}
 
 		if (reg >= ds->num_ports) {
 			dev_err(ds->dev, "port %pOF index %u exceeds num_ports (%zu)\n",
 				port, reg, ds->num_ports);
+			of_node_put(port);
 			err = -EINVAL;
 			goto out_put_node;
 		}
@@ -1387,8 +1390,10 @@ static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
 		dp = dsa_to_port(ds, reg);
 
 		err = dsa_port_parse_of(dp, port);
-		if (err)
+		if (err) {
+			of_node_put(port);
 			goto out_put_node;
+		}
 	}
 
 out_put_node: