[ROSE]: Fix dereference of skb pointer after free.

If rose_route_frame return success we'll dereference a stale pointer.
Likely this is only going to result in bad statistics for the ROSE
interface.

This fixes coverity 946.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/rose/rose_dev.c

@@ -59,6 +59,7 @@ static int rose_rebuild_header(struct sk_buff *skb)
 	struct net_device_stats *stats = netdev_priv(dev);
 	unsigned char *bp = (unsigned char *)skb->data;
 	struct sk_buff *skbn;
+	unsigned int len;
 
 #ifdef CONFIG_INET
 	if (arp_find(bp + 7, skb)) {
@@ -75,6 +76,8 @@ static int rose_rebuild_header(struct sk_buff *skb)
 
 	kfree_skb(skb);
 
+	len = skbn->len;
+
 	if (!rose_route_frame(skbn, NULL)) {
 		kfree_skb(skbn);
 		stats->tx_errors++;
@@ -82,7 +85,7 @@ static int rose_rebuild_header(struct sk_buff *skb)
 	}
 
 	stats->tx_packets++;
-	stats->tx_bytes += skbn->len;
+	stats->tx_bytes += len;
 #endif
 	return 1;
 }