dpaa2-mac: Add a missing of_node_put after of_device_is_available

Add an 'of_node_put()' call when a tested device node is not available.

Fixes: 94ae899b ("dpaa2-mac: add PCS support through the Lynx module")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20201206151339.44306-1-christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c

@@ -269,6 +269,7 @@ static int dpaa2_pcs_create(struct dpaa2_mac *mac,
 
 	if (!of_device_is_available(node)) {
 		netdev_err(mac->net_dev, "pcs-handle node not available\n");
+		of_node_put(node);
 		return -ENODEV;
 	}