Fix asynchronous endpoint stall function and tidy up
ROOL authored
Detail:
  Add missing brace which otherwise meant only the line
    req.bmRequestType = UT_WRITE_ENDPOINT;
  was conditional, rather than the following 6 lines.
  The confusing set of #ifdef __riscos/#endif was masking a missed call to cleartoggle() which would leave the controller and device out of sync.
  Tidy this up, and apply similar to usbd_clear_endpoint_stall() for clarity.
Admin:
  usbdi.c - as detailed above, based on a submission from Colin Granville, with edits.
  usbmodule.c - delete unused DEVICEFSISBROKEN switch, the bug to which it refers was fixed in DeviceFS-0_63 in 2003.

Version 1.26. Tagged as 'USBDriver-1_26'
36bb9aad