net: macb: make macb_tx_skb generic

The macb_tx_skb structure is renamed to macb_tx_buff with
no functional changes.

This is a preparatory step for adding xdp xmit support.

Signed-off-by: Paolo Valerio <pvalerio@redhat.com>

Author: vlrpl

drivers/net/ethernet/cadence/macb.h

@@ -988,15 +988,15 @@ struct macb_dma_desc_ptp {
 /* Scaled PPM fraction */
 #define PPM_FRACTION	16
 
-/* struct macb_tx_skb - data about an skb which is being transmitted
+/* struct macb_tx_buff - data about an skb which is being transmitted
  * @skb: skb currently being transmitted, only set for the last buffer
  *       of the frame
  * @mapping: DMA address of the skb's fragment buffer
  * @size: size of the DMA mapped buffer
  * @mapped_as_page: true when buffer was mapped with skb_frag_dma_map(),
  *                  false when buffer was mapped with dma_map_single()
  */
-struct macb_tx_skb {
+struct macb_tx_buff {
 	struct sk_buff		*skb;
 	dma_addr_t		mapping;
 	size_t			size;
@@ -1290,7 +1290,7 @@ struct macb_queue {
 	spinlock_t		tx_ptr_lock;
 	unsigned int		tx_head, tx_tail;
 	struct macb_dma_desc	*tx_ring;
-	struct macb_tx_skb	*tx_skb;
+	struct macb_tx_buff	*tx_buff;
 	dma_addr_t		tx_ring_dma;
 	struct work_struct	tx_error_task;
 	bool			txubr_pending;
@@ -1376,7 +1376,7 @@ struct macb {
 	int			phy_reset_ms;
 
 	/* AT91RM9200 transmit queue (1 on wire + 1 queued) */
-	struct macb_tx_skb	rm9200_txq[2];
+	struct macb_tx_buff	rm9200_txq[2];
 	unsigned int		max_tx_length;
 
 	u64			ethtool_stats[GEM_STATS_LEN + QUEUE_STATS_LEN * MACB_MAX_QUEUES];