thermal: imx: fix a possible NULL dereference

of_match_device could return NULL, and so cause a NULL pointer
dereference later at line 472:
data->socdata = of_id->data;

For fixing this problem, we use of_device_get_match_data(), this will
simplify the code a little by using a standard function for
getting the match data.

Reported-by: coverity (CID 1324128)
Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/imx_thermal.c

@@ -471,8 +471,6 @@ MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
 
 static int imx_thermal_probe(struct platform_device *pdev)
 {
-	const struct of_device_id *of_id =
-		of_match_device(of_imx_thermal_match, &pdev->dev);
 	struct imx_thermal_data *data;
 	struct regmap *map;
 	int measure_freq;
@@ -490,7 +488,7 @@ static int imx_thermal_probe(struct platform_device *pdev)
 	}
 	data->tempmon = map;
 
-	data->socdata = of_id->data;
+	data->socdata = of_device_get_match_data(&pdev->dev);
 
 	/* make sure the IRQ flag is clear before enabling irq on i.MX6SX */
 	if (data->socdata->version == TEMPMON_IMX6SX) {