usb: xhci-mtk: use @sch_tt to check whether need do TT schedule

It's clearer to use @sch_tt to check whether need do TT schedule,
no function is changed.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/324a76782ccaf857a8f01f67aee435e8ec7d0e28.1615170625.git.chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-mtk-sch.c

@@ -548,7 +548,7 @@ static int check_sch_bw(struct usb_device *udev,
 	min_num_budget = sch_ep->num_budget_microframes;
 	esit_boundary = get_esit_boundary(sch_ep);
 	for (offset = 0; offset < sch_ep->esit; offset++) {
-		if (is_fs_or_ls(udev->speed)) {
+		if (sch_ep->sch_tt) {
 			ret = check_sch_tt(udev, sch_ep, offset);
 			if (ret)
 				continue;
@@ -585,7 +585,7 @@ static int check_sch_bw(struct usb_device *udev,
 	sch_ep->cs_count = min_cs_count;
 	sch_ep->num_budget_microframes = min_num_budget;
 
-	if (is_fs_or_ls(udev->speed)) {
+	if (sch_ep->sch_tt) {
 		/* all offset for tt is not ok*/
 		if (!tt_offset_ok)
 			return -ERANGE;