regulator: fixed: Prevent NULL pointer dereference when !CONFIG_OF

Use of_device_get_match_data which has NULL test for match before
dereference match->data. Add NULL test for drvtype so it still works
for fixed_voltage_ops when !CONFIG_OF.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Philippe Schenker <philippe.schenker@toradex.com>
Link: https://lore.kernel.org/r/20190922022928.28355-1-axel.lin@ingics.com
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
index d90a6fd..f815330 100644
--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -144,8 +144,7 @@ static int reg_fixed_voltage_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct fixed_voltage_config *config;
 	struct fixed_voltage_data *drvdata;
-	const struct fixed_dev_type *drvtype =
-		of_match_device(dev->driver->of_match_table, dev)->data;
+	const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
 	struct regulator_config cfg = { };
 	enum gpiod_flags gflags;
 	int ret;
@@ -177,7 +176,7 @@ static int reg_fixed_voltage_probe(struct platform_device *pdev)
 	drvdata->desc.type = REGULATOR_VOLTAGE;
 	drvdata->desc.owner = THIS_MODULE;
 
-	if (drvtype->has_enable_clock) {
+	if (drvtype && drvtype->has_enable_clock) {
 		drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
 
 		drvdata->enable_clock = devm_clk_get(dev, NULL);