r6040: compile error

drivers/net/r6040.c: In function 'rx_buf_alloc':
drivers/net/r6040.c:262: warning: passing argument 2 of 'pci_map_single' makes pointer from integer without a cast

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
diff --git a/drivers/net/r6040.c b/drivers/net/r6040.c
index 1d7efa2..6a6329e 100644
--- a/drivers/net/r6040.c
+++ b/drivers/net/r6040.c
@@ -260,7 +260,7 @@
 		if (!descptr->skb_ptr)
 			break;
 		descptr->buf = cpu_to_le32(pci_map_single(lp->pdev,
-			descptr->skb_ptr->tail,
+			descptr->skb_ptr->data,
 			MAX_BUF_SIZE, PCI_DMA_FROMDEVICE));
 		descptr->status = 0x8000;
 		descptr = descptr->vndescp;