Input: ads7846 - fix compiler warning in ads7846_probe()

This patch fixes the follwing warning introduced by commit
067fb2f6 ("Input: ads7846 - return error on
regulator_get() failure"):

drivers/input/touchscreen/ads7846.c: In function 'ads7846_probe':
drivers/input/touchscreen/ads7846.c:1167: warning: format '%ld' expects
type 'long int', but argument 4 has type 'int'
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/ads7846.c

@@ -1164,7 +1164,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 	ts->reg = regulator_get(&spi->dev, "vcc");
 	if (IS_ERR(ts->reg)) {
 		err = PTR_ERR(ts->reg);
-		dev_err(&spi->dev, "unable to get regulator: %ld\n", err);
+		dev_err(&spi->dev, "unable to get regulator: %d\n", err);
 		goto err_free_gpio;
 	}