iio: adc: adi-axi-adc: simplify devm_adi_axi_adc_conv_register()

Use devm_add_action_or_reset() instead of devres_alloc() and
devres_add(), which works the same. This will simplify the
code. There is no functional changes.
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/1617881896-3164-2-git-send-email-yangyicong@hisilicon.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/adi-axi-adc.c

@@ -202,29 +202,25 @@ static void adi_axi_adc_conv_unregister(struct adi_axi_adc_conv *conv)
 	kfree(cl);
 }
 
-static void devm_adi_axi_adc_conv_release(struct device *dev, void *res)
+static void devm_adi_axi_adc_conv_release(void *conv)
 {
-	adi_axi_adc_conv_unregister(*(struct adi_axi_adc_conv **)res);
+	adi_axi_adc_conv_unregister(conv);
 }
 
 struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
 							size_t sizeof_priv)
 {
-	struct adi_axi_adc_conv **ptr, *conv;
-
-	ptr = devres_alloc(devm_adi_axi_adc_conv_release, sizeof(*ptr),
-			   GFP_KERNEL);
-	if (!ptr)
-		return ERR_PTR(-ENOMEM);
+	struct adi_axi_adc_conv *conv;
+	int ret;
 
 	conv = adi_axi_adc_conv_register(dev, sizeof_priv);
-	if (IS_ERR(conv)) {
-		devres_free(ptr);
-		return ERR_CAST(conv);
-	}
+	if (IS_ERR(conv))
+		return conv;
 
-	*ptr = conv;
-	devres_add(dev, ptr);
+	ret = devm_add_action_or_reset(dev, devm_adi_axi_adc_conv_release,
+				       conv);
+	if (ret)
+		return ERR_PTR(ret);
 
 	return conv;
 }