[media] si2168: add I2C error handling

Return error from si2168_cmd_execute in case the demodulator returns an
error.
Signed-off-by: NOlli Salonen <olli.salonen@iki.fi>
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/dvb-frontends/si2168.c

@@ -60,6 +60,12 @@ static int si2168_cmd_execute(struct i2c_client *client, struct si2168_cmd *cmd)
 				jiffies_to_msecs(jiffies) -
 				(jiffies_to_msecs(timeout) - TIMEOUT));
 
+		/* error bit set? */
+		if ((cmd->args[0] >> 6) & 0x01) {
+			ret = -EREMOTEIO;
+			goto err_mutex_unlock;
+		}
+
 		if (!((cmd->args[0] >> 7) & 0x01)) {
 			ret = -ETIMEDOUT;
 			goto err_mutex_unlock;