pinctrl: use dev_err() to show message in pinmux_func_name_to_selector()

Use dev_err() rather than pr_err() to display the error message.

pinctrl_dev_get_name(pctldev) is no longer necessary because
dev_err() shows which device the message is related to.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinmux.c

@@ -322,8 +322,7 @@ static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
 		selector++;
 	}
 
-	pr_err("%s does not support function %s\n",
-	       pinctrl_dev_get_name(pctldev), function);
+	dev_err(pctldev->dev, "function '%s' not supported\n", function);
 	return -EINVAL;
 }