[media] si2168: Fix i2c_add_mux_adapter return value

In case of failure the return value was always 0. Return proper
error code (ENODEV) instead.
Signed-off-by: Luis Alves <ljalvs@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/dvb-frontends/si2168.c

@@ -640,8 +640,10 @@ static int si2168_probe(struct i2c_client *client,
 	/* create mux i2c adapter for tuner */
 	s->adapter = i2c_add_mux_adapter(client->adapter, &client->dev, s,
 			0, 0, 0, si2168_select, si2168_deselect);
-	if (s->adapter == NULL)
+	if (s->adapter == NULL) {
+		ret = -ENODEV;
 		goto err;
+	}
 
 	/* create dvb_frontend */
 	memcpy(&s->fe.ops, &si2168_ops, sizeof(struct dvb_frontend_ops));