tlan: add cast needed for proper 64 bit operation

Changes this beauty into a statement that actually has an effect on amd64.
Tested-by: Per Jessen <per@opensuse.org>
Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/tlan.c

@@ -228,7 +228,7 @@ tlan_get_skb(const struct tlan_list *tag)
 	unsigned long addr;
 
 	addr = tag->buffer[9].address;
-	addr |= (tag->buffer[8].address << 16) << 16;
+	addr |= ((unsigned long) tag->buffer[8].address << 16) << 16;
 	return (struct sk_buff *) addr;
 }