4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mark Brown <broonie@kernel.org>

commit 6b7f4e25f3309f106a5c7ff42c8231494cf285d3 upstream.

All regulator_get() variants return either a pointer to a regulator or an
ERR_PTR() so testing for NULL makes no sense and may lead to bugs if we
use NULL as a valid regulator. Fix this by using IS_ERR() as expected.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iio/adc/ad7266.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iio/adc/ad7266.c
+++ b/drivers/iio/adc/ad7266.c

@@ -397,7 +397,7 @@ static int ad7266_probe(struct spi_devic
 	st = iio_priv(indio_dev);
 
 	st->reg = devm_regulator_get(&spi->dev, "vref");
-	if (!IS_ERR_OR_NULL(st->reg)) {
+	if (!IS_ERR(st->reg)) {
 		ret = regulator_enable(st->reg);
 		if (ret)
 			return ret;