[patch] staging: iio: ad799x: cleanup probe error handling

[Dan Carpenter <dan.carpenter@oracle.com>]

My static checker is upset that we check IS_ERR(t->reg) when we know it
is not an ERR_PTR().  The code is harmless but I have cleaned it up and
removed the condition.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c
index 16a8b14..5c95cd9 100644
--- a/drivers/iio/adc/ad799x.c
+++ b/drivers/iio/adc/ad799x.c
@@ -717,7 +717,7 @@ static int ad799x_probe(struct i2c_client *client,
 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 		&ad799x_trigger_handler, NULL);
 	if (ret)
-		goto error_disable_reg;
+		goto error_disable_vref;
 
 	if (client->irq > 0) {
 		ret = devm_request_threaded_irq(&client->dev,
@@ -739,11 +739,10 @@ static int ad799x_probe(struct i2c_client *client,
 
 error_cleanup_ring:
 	iio_triggered_buffer_cleanup(indio_dev);
+error_disable_vref:
+	regulator_disable(st->vref);
 error_disable_reg:
-	if (!IS_ERR(st->vref))
-		regulator_disable(st->vref);
-	if (!IS_ERR(st->reg))
-		regulator_disable(st->reg);
+	regulator_disable(st->reg);
 
 	return ret;
 }