gianfar: ethtool: Fix refcount leak in gfar_get_ts_info

The of_find_compatible_node() function returns a node pointer with
refcount incremented, We should use of_node_put() on it when done
Add the missing of_node_put() to release the refcount.

Fixes: 7349a74e ("net: ethernet: gianfar_ethtool: get phc index through drvdata")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Link: https://lore.kernel.org/r/20220310015313.14938-1-linmq006@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/gianfar_ethtool.c

@@ -1464,6 +1464,7 @@ static int gfar_get_ts_info(struct net_device *dev,
 	ptp_node = of_find_compatible_node(NULL, NULL, "fsl,etsec-ptp");
 	if (ptp_node) {
 		ptp_dev = of_find_device_by_node(ptp_node);
+		of_node_put(ptp_node);
 		if (ptp_dev)
 			ptp = platform_get_drvdata(ptp_dev);
 	}