mac80211: move TX info into skb->cb

This patch converts mac80211 and all drivers to have transmit
information and status in skb->cb rather than allocating extra
memory for it and copying all the data around. To make it fit,
a union is used where only data that is necessary for all steps
is kept outside of the union.

A number of fixes were done by Ivo, as well as the rt2x00 part
of this patch.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00pci.h b/drivers/net/wireless/rt2x00/rt2x00pci.h
index 557d15a..37c851e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00pci.h
+++ b/drivers/net/wireless/rt2x00/rt2x00pci.h
@@ -91,8 +91,7 @@
  * TX data handlers.
  */
 int rt2x00pci_write_tx_data(struct rt2x00_dev *rt2x00dev,
-			    struct data_queue *queue, struct sk_buff *skb,
-			    struct ieee80211_tx_control *control);
+			    struct data_queue *queue, struct sk_buff *skb);
 
 /**
  * struct queue_entry_priv_pci: Per entry PCI specific information
@@ -101,7 +100,6 @@
  * @desc_dma: DMA pointer to &desc.
  * @data: Pointer to device's entry memory.
  * @data_dma: DMA pointer to &data.
- * @control: mac80211 control structure used to transmit data.
  */
 struct queue_entry_priv_pci {
 	__le32 *desc;
@@ -109,8 +107,6 @@
 
 	void *data;
 	dma_addr_t data_dma;
-
-	struct ieee80211_tx_control control;
 };
 
 /**