Fix "Task not known" error masking real error message in some situations
Jeffrey Lee authored
Detail:
  c/armsys - _desktop_report now always caches the error message in the local error block. This avoids the error potentially being overwritten with "Task not known" if TaskManager_TaskNameFromHandle fails.
Admin:
  Tested on Raspberry Pi


Version 5.72. Tagged as 'RISC_OSLib-5_72'
2d5cdfa8