net/xen-netback: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Paul Durrant <paul.durrant@citrix.com>
Cc: xen-devel@lists.xenproject.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index dcfcb15..5cbe0ae 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -520,7 +520,7 @@ int xenvif_init_queue(struct xenvif_queue *queue)
 
 	queue->credit_bytes = queue->remaining_credit = ~0UL;
 	queue->credit_usec  = 0UL;
-	setup_timer(&queue->credit_timeout, xenvif_tx_credit_callback, 0UL);
+	timer_setup(&queue->credit_timeout, xenvif_tx_credit_callback, 0);
 	queue->credit_window_start = get_jiffies_64();
 
 	queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;