[patch] stmmac: fix an error code in stmmac_ptp_register()

[Dan Carpenter]

PTR_ERR(NULL) is success.  We have to preserve the error code earlier.

Fixes: 7086605a6ab5 ("stmmac: fix error check when init ptp")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
---
Applies to net.git tree.

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c 
b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
index 289d527..5d61fb2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
@@ -185,8 +185,10 @@ int stmmac_ptp_register(struct stmmac_priv *priv)
        priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,
                                             priv->device);
        if (IS_ERR(priv->ptp_clock)) {
+               int ret = PTR_ERR(priv->ptp_clock);
+
                priv->ptp_clock = NULL;
-               return PTR_ERR(priv->ptp_clock);
+               return ret;
        }
 
        spin_lock_init(&priv->ptp_lock);