wifi: iwlwifi: dbg-tlv: avoid extra allocation/copy

In iwl_dbg_tlv_alloc_trigger() the code makes a copy just
to modify it and pass it to another function to make a copy
again. Change the API to return the copy so the adjustment
can be done without another copy.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240128084842.075c8b9f7030.Id5a61e1a87a9c6932727fb4e2c9b54ed6070362a@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>