[media] cx231xx: use 1 byte read for i2c scan

Now cx231xx_i2c_check_for_device works like i2c_check_for_device of em28xx driver.

For me this fixes scanning of all ports but port 2.
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/usb/cx231xx/cx231xx-i2c.c

@@ -350,14 +350,15 @@ static int cx231xx_i2c_check_for_device(struct i2c_adapter *i2c_adap,
 	struct cx231xx *dev = bus->dev;
 	struct cx231xx_i2c_xfer_data req_data;
 	int status = 0;
+	u8 buf[1];
 
 	/* prepare xfer_data struct */
 	req_data.dev_addr = msg->addr;
-	req_data.direction = msg->flags;
+	req_data.direction = I2C_M_RD;
 	req_data.saddr_len = 0;
 	req_data.saddr_dat = 0;
-	req_data.buf_size = 0;
-	req_data.p_buffer = NULL;
+	req_data.buf_size = 1;
+	req_data.p_buffer = buf;
 
 	/* usb send command */
 	status = dev->cx231xx_send_usb_command(bus, &req_data);