backlight: 88pm860x_bl - potential memory leak

I added a kfree() on the error path.  I don't really expect it to affect
anyone, but it's easy and makes the static checkers happy.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

drivers/video/backlight/88pm860x_bl.c

@@ -222,6 +222,7 @@ static int pm860x_backlight_probe(struct platform_device *pdev)
 	data->port = __check_device(pdata, name);
 	if (data->port < 0) {
 		dev_err(&pdev->dev, "wrong platform data is assigned");
+		kfree(data);
 		return -EINVAL;
 	}