dl2k: nulify fraginfo after unmap

Patch fixes: "DMA-API: device driver tries to free an invalid DMA
memory address" warning reported here:
https://bugzilla.redhat.com/show_bug.cgi?id=639824

Reported-by: Frantisek Hanzlik <franta@hanzlici.cz>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dl2k.c

diff --git a/drivers/net/dl2k.c b/drivers/net/dl2k.c
index e1a8216..c05db60 100644
--- a/drivers/net/dl2k.c
+++ b/drivers/net/dl2k.c
@@ -1753,8 +1753,6 @@
 
 	/* Free all the skbuffs in the queue. */
 	for (i = 0; i < RX_RING_SIZE; i++) {
-		np->rx_ring[i].status = 0;
-		np->rx_ring[i].fraginfo = 0;
 		skb = np->rx_skbuff[i];
 		if (skb) {
 			pci_unmap_single(np->pdev,
@@ -1763,6 +1761,8 @@
 			dev_kfree_skb (skb);
 			np->rx_skbuff[i] = NULL;
 		}
+		np->rx_ring[i].status = 0;
+		np->rx_ring[i].fraginfo = 0;
 	}
 	for (i = 0; i < TX_RING_SIZE; i++) {
 		skb = np->tx_skbuff[i];