tg3: Reintroduce tg3_tx_ring_info

The following patches will require the use of an additional flag in the
ring_info structure.  The use of this flag is tx path specific, so this
patch defines a specialized ring_info structure.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 691539b..f6986ca 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2652,6 +2652,11 @@
 	DEFINE_DMA_UNMAP_ADDR(mapping);
 };
 
+struct tg3_tx_ring_info {
+	struct sk_buff			*skb;
+	DEFINE_DMA_UNMAP_ADDR(mapping);
+};
+
 struct tg3_link_config {
 	/* Describes what we're trying to get. */
 	u32				advertising;
@@ -2816,7 +2821,7 @@
 	u32				last_tx_cons;
 	u32				prodmbox;
 	struct tg3_tx_buffer_desc	*tx_ring;
-	struct ring_info		*tx_buffers;
+	struct tg3_tx_ring_info		*tx_buffers;
 
 	dma_addr_t			status_mapping;
 	dma_addr_t			rx_rcb_mapping;