backlight: adp5520: Fix error handling in adp5520_bl_probe()

If adp5520_bl_setup() fails, sysfs group left unremoved.

By the way, fix overcomplicated assignement of error code.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/video/backlight/adp5520_bl.c

@@ -332,10 +332,18 @@ static int adp5520_bl_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, bl);
-	ret |= adp5520_bl_setup(bl);
+	ret = adp5520_bl_setup(bl);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup\n");
+		if (data->pdata->en_ambl_sens)
+			sysfs_remove_group(&bl->dev.kobj,
+					&adp5520_bl_attr_group);
+		return ret;
+	}
+
 	backlight_update_status(bl);
 
-	return ret;
+	return 0;
 }
 
 static int adp5520_bl_remove(struct platform_device *pdev)