regulator: fixed: Ensure enable_counter is correct if reg_domain_disable fails

dev_pm_genpd_set_performance_state() may fail, so had better to check it's
return value before decreasing priv->enable_counter.

Fixes: bf3a28cf ("regulator: fixed: support using power domain for enable/disable")
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20210520111811.1806293-1-axel.lin@ingics.comSigned-off-by: NMark Brown <broonie@kernel.org>

drivers/regulator/fixed.c

@@ -88,10 +88,15 @@ static int reg_domain_disable(struct regulator_dev *rdev)
 {
 	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
 	struct device *dev = rdev->dev.parent;
+	int ret;
+
+	ret = dev_pm_genpd_set_performance_state(dev, 0);
+	if (ret)
+		return ret;
 
 	priv->enable_counter--;
 
-	return dev_pm_genpd_set_performance_state(dev, 0);
+	return 0;
 }
 
 static int reg_is_enabled(struct regulator_dev *rdev)