iio: pressure: rohm-bm1390: Return error when read fails

The data reading function ignores the cached error value, and
unconditionally returns 0. Return cached 'ret' -value after stopping
the measurement so user knows if read failed and data is garbage.

Fixes: 534674463a ("iio: bm1390: simplify using guard(mutex)")
Signed-off-by: Matti Vaittinen <[email protected]>
Cc: <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

drivers/iio/pressure/rohm-bm1390.c

@@ -289,7 +289,7 @@ static int bm1390_read_data(struct bm1390_data *data,
 	if (warn)
 		dev_warn(data->dev, "Failed to stop measurement (%d)\n", warn);
 
-	return 0;
+	return ret;
 }
 
 static int bm1390_read_raw(struct iio_dev *idev,