mtd: rawnand: orion: Use devm_clk_get_optional()

Use devm_clk_get_optional() instead of hand writing it.

While at it, use dev_err_probe() to further simplify the code. This is also
less verbose if clk_get() returns -EPROBE_DEFER.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/a5bde48e3e1165dd65d1d1c1739e03ace1bef5d3.1659907229.git.christophe.jaillet@wanadoo.fr

drivers/mtd/nand/raw/orion_nand.c

@@ -170,18 +170,11 @@ static int __init orion_nand_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, info);
 
-	/* Not all platforms can gate the clock, so it is not
-	   an error if the clock does not exists. */
-	info->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(info->clk)) {
-		ret = PTR_ERR(info->clk);
-		if (ret == -ENOENT) {
-			info->clk = NULL;
-		} else {
-			dev_err(&pdev->dev, "failed to get clock!\n");
-			return ret;
-		}
-	}
+	/* Not all platforms can gate the clock, so it is optional. */
+	info->clk = devm_clk_get_optional(&pdev->dev, NULL);
+	if (IS_ERR(info->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(info->clk),
+				     "failed to get clock!\n");
 
 	ret = clk_prepare_enable(info->clk);
 	if (ret) {