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/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
index a8d062f..ad7422e 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.h
+++ b/drivers/net/wireless/iwlwifi/iwl-core.h
@@ -207,8 +207,7 @@
 * TX
 ******************************************************/
 int iwl_txq_ctx_reset(struct iwl_priv *priv);
-int iwl_tx_skb(struct iwl_priv *priv,
-		struct sk_buff *skb, struct ieee80211_tx_control *ctl);
+int iwl_tx_skb(struct iwl_priv *priv, struct sk_buff *skb);
 /* FIXME: remove when free Tx is fully merged into iwlcore */
 int iwl_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq);
 void iwl_hw_txq_ctx_free(struct iwl_priv *priv);