net: dsa: Add missing of_node_put() in dsa_port_parse_of

The device_node pointer is returned by of_parse_phandle()  with refcount
incremented. We should use of_node_put() on it when done.

Fixes: 6d4e5c57 ("net: dsa: get port type at parse time")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220316082602.10785-1-linmq006@gmail.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

net/dsa/dsa2.c

@@ -1436,6 +1436,7 @@ static int dsa_port_parse_of(struct dsa_port *dp, struct device_node *dn)
 		const char *user_protocol;
 
 		master = of_find_net_device_by_node(ethernet);
+		of_node_put(ethernet);
 		if (!master)
 			return -EPROBE_DEFER;