xhci: replace 'xhci->cmd_ring->dequeue' with 'trb' in stop_ep cmd handler

This patch replaces 'xhci->cmd_ring->dequeue' with 'trb', the address of
the command TRB, since it is available to reduce line length.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index e0b5920..61243f5 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -779,10 +779,8 @@
 
 	struct xhci_dequeue_state deq_state;
 
-	if (unlikely(TRB_TO_SUSPEND_PORT(
-			     le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3])))) {
-		slot_id = TRB_TO_SLOT_ID(
-			le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3]));
+	if (unlikely(TRB_TO_SUSPEND_PORT(le32_to_cpu(trb->generic.field[3])))) {
+		slot_id = TRB_TO_SLOT_ID(le32_to_cpu(trb->generic.field[3]));
 		virt_dev = xhci->devs[slot_id];
 		if (virt_dev)
 			handle_cmd_in_cmd_wait_list(xhci, virt_dev,