greybus: es2: Don't use stack memory as USB request data

int es2_ap_csi_setup(struct gb_host_device *hd, bool start,

		     struct es2_ap_csi_config *cfg)

{

	struct es2_ap_csi_config_request cfg_req;

	struct es2_ap_csi_config_request *cfg_req;

	struct es2_ap_dev *es2 = hd_to_es2(hd);

	struct usb_device *udev = es2->usb_dev;

	int retval;

	cfg_req.csi_id = cfg->csi_id;

	cfg_req = kzalloc(sizeof(*cfg_req), GFP_KERNEL);

	if (!cfg_req)

		return -ENOMEM;

	cfg_req->csi_id = cfg->csi_id;

	if (start) {

		cfg_req.clock_mode = cfg->clock_mode;

		cfg_req.num_lanes = cfg->num_lanes;

		cfg_req.padding = 0;

		cfg_req.bus_freq = cpu_to_le32(cfg->bus_freq);

	} else {

		cfg_req.clock_mode = 0;

		cfg_req.num_lanes = 0;

		cfg_req.padding = 0;

		cfg_req.bus_freq = 0;

		cfg_req->clock_mode = cfg->clock_mode;

		cfg_req->num_lanes = cfg->num_lanes;

		cfg_req->bus_freq = cpu_to_le32(cfg->bus_freq);

	}

	retval = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),

				 REQUEST_CSI_TX_CONTROL,

				 USB_DIR_OUT | USB_TYPE_VENDOR |

				 USB_RECIP_INTERFACE, 0, 0, &cfg_req,

				 sizeof(cfg_req), ES2_TIMEOUT);

	if (retval < 0) {

				 USB_RECIP_INTERFACE, 0, 0, cfg_req,

				 sizeof(*cfg_req), ES2_TIMEOUT);

	if (retval < 0)

		dev_err(&udev->dev, "failed to setup csi: %d\n", retval);

		return retval;

	}

	return 0;

	kfree(cfg_req);

	return retval;

}

EXPORT_SYMBOL_GPL(es2_ap_csi_setup);