ide-cd: kill whole failed request in ide_cd_do_request()

Untangling cdrom_end_request() uncovered an error in completing
failed requests in ide_cd_do_request().  Fix it.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>