mfd: Convert wm831x core driver to devm_kzalloc()

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/wm831x-spi.c b/drivers/mfd/wm831x-spi.c
index 8d6a9a9..a43cba3 100644
--- a/drivers/mfd/wm831x-spi.c
+++ b/drivers/mfd/wm831x-spi.c
@@ -30,7 +30,7 @@
 
 	type = (enum wm831x_parent)id->driver_data;
 
-	wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL);
+	wm831x = devm_kzalloc(&spi->dev, sizeof(struct wm831x), GFP_KERNEL);
 	if (wm831x == NULL)
 		return -ENOMEM;
 
@@ -45,7 +45,6 @@
 		ret = PTR_ERR(wm831x->regmap);
 		dev_err(wm831x->dev, "Failed to allocate register map: %d\n",
 			ret);
-		kfree(wm831x);
 		return ret;
 	}