iio: magnetometer: ak8975: Add missed pm_runtime_put_autosuspend() call

On the failure in the ak8975_read_axis() the PM runtime gets unbalanced.
Balance it by calling pm_runtime_put_autosuspend() on error path as well.

Fixes: cde4cb5 ("iio: magn: ak8975: deploy runtime and system PM")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260505-magnetometer-fixes-v5-0-831b9b5550fc%40gmail.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Author: andy-shev

drivers/iio/magnetometer/ak8975.c

@@ -784,6 +784,7 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
 
 exit:
 	mutex_unlock(&data->lock);
+	pm_runtime_put_autosuspend(&data->client->dev);
 	dev_err(&client->dev, "Error in reading axis\n");
 	return ret;
 }