iwlagn: simplify the iwl_device_cmd layout

This simplifies both the transport layer and the upper layer.

Kill the union in the device command, which avoids the funny syntax
we had: cmd->cmd.payload.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
index ca13eeb..dbb7eb3 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
@@ -1043,7 +1043,7 @@
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	struct iwl_tx_cmd *tx_cmd = &dev_cmd->cmd.tx;
+	struct iwl_tx_cmd *tx_cmd = (struct iwl_tx_cmd *) dev_cmd->payload;
 	struct iwl_cmd_meta *out_meta;
 	struct iwl_tx_queue *txq;
 	struct iwl_queue *q;