cb9a645c8f
A rework of the scheduler unit tests removed the done_list. That list is
still mentioned in the mock test header.
Remove that relict.
Fixes: 4576de9b79 ("drm/sched/tests: Implement cancel_job() callback")
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://lore.kernel.org/r/20250919064450.147176-2-phasta@kernel.org