iio: dac: ad5791: Use devm_* APIs

devm_* APIs are device managed and make code simpler.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/dac/ad5791.c b/drivers/iio/dac/ad5791.c
index 97c1e5d..ce74589 100644
--- a/drivers/iio/dac/ad5791.c
+++ b/drivers/iio/dac/ad5791.c
@@ -349,17 +349,15 @@
 	struct ad5791_state *st;
 	int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
 
-	indio_dev = iio_device_alloc(sizeof(*st));
-	if (indio_dev == NULL) {
-		ret = -ENOMEM;
-		goto error_ret;
-	}
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
 	st = iio_priv(indio_dev);
-	st->reg_vdd = regulator_get(&spi->dev, "vdd");
+	st->reg_vdd = devm_regulator_get(&spi->dev, "vdd");
 	if (!IS_ERR(st->reg_vdd)) {
 		ret = regulator_enable(st->reg_vdd);
 		if (ret)
-			goto error_put_reg_pos;
+			return ret;
 
 		ret = regulator_get_voltage(st->reg_vdd);
 		if (ret < 0)
@@ -368,11 +366,11 @@
 		pos_voltage_uv = ret;
 	}
 
-	st->reg_vss = regulator_get(&spi->dev, "vss");
+	st->reg_vss = devm_regulator_get(&spi->dev, "vss");
 	if (!IS_ERR(st->reg_vss)) {
 		ret = regulator_enable(st->reg_vss);
 		if (ret)
-			goto error_put_reg_neg;
+			goto error_disable_reg_pos;
 
 		ret = regulator_get_voltage(st->reg_vss);
 		if (ret < 0)
@@ -428,19 +426,9 @@
 error_disable_reg_neg:
 	if (!IS_ERR(st->reg_vss))
 		regulator_disable(st->reg_vss);
-error_put_reg_neg:
-	if (!IS_ERR(st->reg_vss))
-		regulator_put(st->reg_vss);
-
 error_disable_reg_pos:
 	if (!IS_ERR(st->reg_vdd))
 		regulator_disable(st->reg_vdd);
-error_put_reg_pos:
-	if (!IS_ERR(st->reg_vdd))
-		regulator_put(st->reg_vdd);
-	iio_device_free(indio_dev);
-error_ret:
-
 	return ret;
 }
 
@@ -450,16 +438,11 @@
 	struct ad5791_state *st = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
-	if (!IS_ERR(st->reg_vdd)) {
+	if (!IS_ERR(st->reg_vdd))
 		regulator_disable(st->reg_vdd);
-		regulator_put(st->reg_vdd);
-	}
 
-	if (!IS_ERR(st->reg_vss)) {
+	if (!IS_ERR(st->reg_vss))
 		regulator_disable(st->reg_vss);
-		regulator_put(st->reg_vss);
-	}
-	iio_device_free(indio_dev);
 
 	return 0;
 }