usbnet: correct speed testing

Allow for SS+ USB

Signed-off-by: Oliver Neukum <ONeukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 1079812..4837854 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -356,6 +356,7 @@
 		dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 		break;
 	case USB_SPEED_SUPER:
+	case USB_SPEED_SUPER_PLUS:
 		/*
 		 * Not take default 5ms qlen for super speed HC to
 		 * save memory, and iperf tests show 2.5ms qlen can