[media] af9035: add missing error check

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/dvb-usb/af9035.c

@@ -400,6 +400,8 @@ static int af9035_download_firmware(struct usb_device *udev,
 		/* download begin packet */
 		req.cmd = CMD_FW_DL_BEGIN;
 		ret = af9035_ctrl_msg(udev, &req);
+		if (ret < 0)
+			goto err;
 
 		/* download firmware packet(s) */
 		for (j = HDR_SIZE + hdr_data_len; j > 0; j -= MAX_DATA) {