Input: ads7846 - correct log message for spi_sync() errors

While searching for users of spi_async() I got a false positive in the
ads7846 driver, fix that.
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/ads7846.c

@@ -706,7 +706,7 @@ static void ads7846_read_state(struct ads7846 *ts)
 		m = &ts->msg[msg_idx];
 		error = spi_sync(ts->spi, m);
 		if (error) {
-			dev_err(&ts->spi->dev, "spi_async --> %d\n", error);
+			dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 			packet->tc.ignore = true;
 			return;
 		}