usb: host: xhci: make use of new usb_endpoint_maxp_mult()

We have introduced a helper to calculate multiplier
value from wMaxPacketSize. Start using it.

Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 6afe323..679672d 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1370,7 +1370,7 @@
 	if (udev->speed == USB_SPEED_HIGH &&
 	    (usb_endpoint_xfer_isoc(&ep->desc) ||
 	     usb_endpoint_xfer_int(&ep->desc)))
-		return (usb_endpoint_maxp(&ep->desc) & 0x1800) >> 11;
+		return usb_endpoint_maxp_mult(&ep->desc) - 1;
 
 	return 0;
 }
@@ -1416,9 +1416,9 @@
 		return le16_to_cpu(ep->ss_ep_comp.wBytesPerInterval);
 
 	max_packet = GET_MAX_PACKET(usb_endpoint_maxp(&ep->desc));
-	max_burst = (usb_endpoint_maxp(&ep->desc) & 0x1800) >> 11;
+	max_burst = usb_endpoint_maxp_mult(&ep->desc);
 	/* A 0 in max burst means 1 transfer per ESIT */
-	return max_packet * (max_burst + 1);
+	return max_packet * max_burst;
 }
 
 /* Set up an endpoint with one ring segment.  Do not allocate stream rings.