usb: host: usbh_ch9: add ASSERT for unresolved data stage conditions

Do not explicitly check buf parameter in usbh_req_setup()
but add ASSERT to check unresolved data stage conditions.

Signed-off-by: Johann Fischer <[email protected]>

Author: jfischer-no

subsys/usb/host/usbh_ch9.c

@@ -60,7 +60,9 @@ int usbh_req_setup(struct usb_device *const udev,
 
 	memcpy(xfer->setup_pkt, &req, sizeof(req));
 
-	if (wLength && buf != NULL) {
+	__ASSERT((buf != NULL && wLength) || (buf == NULL && !wLength),
+		 "Unresolved conditions for data stage");
+	if (wLength) {
 		ret = usbh_xfer_buf_add(udev, xfer, buf);
 		if (ret) {
 			goto buf_alloc_err;