r8169: use devm_clk_get_optional_enabled() to simplify the code

Now that we have devm_clk_get_optional_enabled(), we don't have to
open-code it.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169_main.c

@@ -5119,37 +5119,6 @@ static int rtl_jumbo_max(struct rtl8169_private *tp)
 	}
 }
 
-static void rtl_disable_clk(void *data)
-{
-	clk_disable_unprepare(data);
-}
-
-static int rtl_get_ether_clk(struct rtl8169_private *tp)
-{
-	struct device *d = tp_to_dev(tp);
-	struct clk *clk;
-	int rc;
-
-	clk = devm_clk_get(d, "ether_clk");
-	if (IS_ERR(clk)) {
-		rc = PTR_ERR(clk);
-		if (rc == -ENOENT)
-			/* clk-core allows NULL (for suspend / resume) */
-			rc = 0;
-		else
-			dev_err_probe(d, rc, "failed to get clk\n");
-	} else {
-		tp->clk = clk;
-		rc = clk_prepare_enable(clk);
-		if (rc)
-			dev_err(d, "failed to enable clk: %d\n", rc);
-		else
-			rc = devm_add_action_or_reset(d, rtl_disable_clk, clk);
-	}
-
-	return rc;
-}
-
 static void rtl_init_mac_address(struct rtl8169_private *tp)
 {
 	u8 mac_addr[ETH_ALEN] __aligned(2) = {};
@@ -5213,9 +5182,9 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		return -ENOMEM;
 
 	/* Get the *optional* external "ether_clk" used on some boards */
-	rc = rtl_get_ether_clk(tp);
-	if (rc)
-		return rc;
+	tp->clk = devm_clk_get_optional_enabled(&pdev->dev, "ether_clk");
+	if (IS_ERR(tp->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(tp->clk), "failed to get ether_clk\n");
 
 	/* enable device (incl. PCI PM wakeup and hotplug setup) */
 	rc = pcim_enable_device(pdev);