iwlwifi: fix up command sending

The current command sending in iwlwifi is a bit of a mess:
 1) there is a struct, iwl_cmd, that contains both driver
    and device data in a single packed structure -- this
    is very confusing
 2) the on-stack data and the command metadata share a
    structure by embedding the latter in the former, which
    is also rather confusing because it leads to weird
    unions and similarly odd constructs
 3) each txq always has enough space for 256 commands,
    even if only 32 end up being used

This patch fixes these things:
 1) rename iwl_cmd to iwl_device_cmd and keep track of
    command metadata and device command separately, in
    two arrays in each tx queue
 2) remove the 'meta' member from iwl_host_cmd and only
    put in the required members
 3) allocate the cmd/meta arrays separately instead of
    embedding them into the txq structure

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
index 00398d9..c4c916d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-scan.c
+++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
@@ -115,7 +115,7 @@
 	struct iwl_rx_packet *res;
 	struct iwl_host_cmd cmd = {
 		.id = REPLY_SCAN_ABORT_CMD,
-		.meta.flags = CMD_WANT_SKB,
+		.flags = CMD_WANT_SKB,
 	};
 
 	/* If there isn't a scan actively going on in the hardware
@@ -132,7 +132,7 @@
 		return ret;
 	}
 
-	res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
+	res = (struct iwl_rx_packet *)cmd.reply_skb->data;
 	if (res->u.status != CAN_ABORT_STATUS) {
 		/* The scan abort will return 1 for success or
 		 * 2 for "failure".  A failure condition can be
@@ -146,7 +146,7 @@
 	}
 
 	priv->alloc_rxb_skb--;
-	dev_kfree_skb_any(cmd.meta.u.skb);
+	dev_kfree_skb_any(cmd.reply_skb);
 
 	return ret;
 }
@@ -567,7 +567,7 @@
 	struct iwl_host_cmd cmd = {
 		.id = REPLY_SCAN_CMD,
 		.len = sizeof(struct iwl_scan_cmd),
-		.meta.flags = CMD_SIZE_HUGE,
+		.flags = CMD_SIZE_HUGE,
 	};
 	struct iwl_scan_cmd *scan;
 	struct ieee80211_conf *conf = NULL;