wifi: iwlwifi: fw: Fix possible memory leak in iwl_fw_dbg_collect

Ensure descriptor is freed on error to avoid memory leak.

Signed-off-by: Pagadala Yesu Anjaneyulu <pagadala.yesu.anjaneyulu@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250611222325.8158d15ec866.Ifa3e422c302397111f20a16da7509e6574bc19e3@changeid