wifi: iwlwifi: tracing: fix condition to allocate buf1

There's no need to allocate buf1 if we're not going to
write anything to it, and the condition for writing is
(correctly) "hdr_len > 0 && !iwl_trace_data()". Also
allocate the event space only under the same condition.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240512152312.a11e6490d053.Ie090beea70d2f271bb22c9b0e287dbd342fb2a96@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/iwl-devtrace-iwlwifi.h

@@ -4,7 +4,7 @@
  * Copyright(c) 2009 - 2014 Intel Corporation. All rights reserved.
  * Copyright(c) 2015 Intel Mobile Communications GmbH
  * Copyright(c) 2016 - 2017 Intel Deutschland GmbH
- * Copyright(c) 2018, 2023  Intel Corporation
+ * Copyright(c) 2018, 2023-2024  Intel Corporation
  *****************************************************************************/
 
 #if !defined(__IWLWIFI_DEVICE_TRACE_IWLWIFI) || defined(TRACE_HEADER_MULTI_READ)
@@ -88,8 +88,8 @@ TRACE_EVENT(iwlwifi_dev_tx,
 		 * for the possible padding).
 		 */
 		__dynamic_array(u8, buf0, buf0_len)
-		__dynamic_array(u8, buf1, hdr_len > 0 && iwl_trace_data(skb) ?
-						0 : skb->len - hdr_len)
+		__dynamic_array(u8, buf1, hdr_len > 0 && !iwl_trace_data(skb) ?
+						skb->len - hdr_len : 0)
 	),
 	TP_fast_assign(
 		DEV_ASSIGN;