usb: dwc2: simplify wait_for_chhltd

toggle is never NULL. Simplify the code by removing handling of when it
is NULL.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index e8a7e71..5a1c44a 100644
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -724,11 +724,9 @@
 	hctsiz = readl(&hc_regs->hctsiz);
 	*sub = (hctsiz & DWC2_HCTSIZ_XFERSIZE_MASK) >>
 		DWC2_HCTSIZ_XFERSIZE_OFFSET;
-	if (toggle)
-		*toggle = (hctsiz & DWC2_HCTSIZ_PID_MASK) >>
-			DWC2_HCTSIZ_PID_OFFSET;
+	*toggle = (hctsiz & DWC2_HCTSIZ_PID_MASK) >> DWC2_HCTSIZ_PID_OFFSET;
 
-	debug("%s: sub=%u toggle=%d\n", __func__, *sub, toggle ? *toggle : -1);
+	debug("%s: sub=%u toggle=%d\n", __func__, *sub, *toggle);
 
 	return 0;
 }