xhci: Convert to use list_count()

The list API now provides the list_count() to help with counting
existing nodes in the list. Utilise it.
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221123144901.40493-4-andriy.shevchenko@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-ring.c

@@ -2532,7 +2532,6 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 	union xhci_trb *ep_trb;
 	int status = -EINPROGRESS;
 	struct xhci_ep_ctx *ep_ctx;
-	struct list_head *tmp;
 	u32 trb_comp_code;
 	int td_num = 0;
 	bool handling_skipped_tds = false;
@@ -2580,10 +2579,8 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 	}
 
 	/* Count current td numbers if ep->skip is set */
-	if (ep->skip) {
-		list_for_each(tmp, &ep_ring->td_list)
-			td_num++;
-	}
+	if (ep->skip)
+		td_num += list_count(&ep_ring->td_list);
 
 	/* Look for common error cases */
 	switch (trb_comp_code) {