net: bcmgenet: Remove checks on clock handles

Instead of multiplying the number of checks for IS_ERR(priv->clk),
simply NULLify the 'struct clk' pointer which is something the Linux
common clock framework perfectly deals with and does early return for
each and every single clk_* API functions.

Having every single function check for !IS_ERR(priv->clk) is both
redundant and error prone, as it turns out, we were doing it for the
main GENET clock: priv->clk, but not for the Wake-on-LAN or EEE clock,
so let's just be consistent here.

Signed-off-by: Florian Fainelli <[e-mail]>
Acked-by: Petri Gynther <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/broadcom/genet/bcmgenet.c

···
 	netif_dbg(priv, ifup, dev, "bcmgenet_open\n");
 
 	/* Turn on the clock */
-	if (!IS_ERR(priv->clk))
-		clk_prepare_enable(priv->clk);
+	clk_prepare_enable(priv->clk);
 
 	/* If this is an internal GPHY, power it back on now, before UniMAC is
 	 * brought out of reset as absolutely no UniMAC activity is allowed
···
 err_fini_dma:
 	bcmgenet_fini_dma(priv);
 err_clk_disable:
-	if (!IS_ERR(priv->clk))
-		clk_disable_unprepare(priv->clk);
+	clk_disable_unprepare(priv->clk);
 	return ret;
 }
 
···
 	if (priv->internal_phy)
 		ret = bcmgenet_power_down(priv, GENET_POWER_PASSIVE);
 
-	if (!IS_ERR(priv->clk))
-		clk_disable_unprepare(priv->clk);
+	clk_disable_unprepare(priv->clk);
 
 	return ret;
 }
···
 		priv->version = pd->genet_version;
 
 	priv->clk = devm_clk_get(&priv->pdev->dev, "enet");
-	if (IS_ERR(priv->clk))
+	if (IS_ERR(priv->clk)) {
 		dev_warn(&priv->pdev->dev, "failed to get enet clock\n");
+		priv->clk = NULL;
+	}
 
-	if (!IS_ERR(priv->clk))
-		clk_prepare_enable(priv->clk);
+	clk_prepare_enable(priv->clk);
 
 	bcmgenet_set_hw_params(priv);
 
···
 	INIT_WORK(&priv->bcmgenet_irq_work, bcmgenet_irq_task);
 
 	priv->clk_wol = devm_clk_get(&priv->pdev->dev, "enet-wol");
-	if (IS_ERR(priv->clk_wol))
+	if (IS_ERR(priv->clk_wol)) {
 		dev_warn(&priv->pdev->dev, "failed to get enet-wol clock\n");
+		priv->clk_wol = NULL;
+	}
 
 	priv->clk_eee = devm_clk_get(&priv->pdev->dev, "enet-eee");
 	if (IS_ERR(priv->clk_eee)) {
···
 	netif_carrier_off(dev);
 
 	/* Turn off the main clock, WOL clock is handled separately */
-	if (!IS_ERR(priv->clk))
-		clk_disable_unprepare(priv->clk);
+	clk_disable_unprepare(priv->clk);
 
 	err = register_netdev(dev);
 	if (err)
···
 	return err;
 
 err_clk_disable:
-	if (!IS_ERR(priv->clk))
-		clk_disable_unprepare(priv->clk);
+	clk_disable_unprepare(priv->clk);
 err:
 	free_netdev(dev);
 	return err;