drm/i915/selftests: Create mock_engine() under struct_mutex

Calling mock_engine() calls i915_timeline_init() and that requires
struct_mutex to be held as it adds itself to the global list of
timelines. This error was introduced by commit a89d1f921c15 ("drm/i915:
Split i915_gem_timeline into individual timelines") but the issue was
masked in CI by the earlier lockdep spam.

Fixes: a89d1f921c15 ("drm/i915: Split i915_gem_timeline into individual timelines")
Signed-off-by: Chris Wilson <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Michel Thierry <[email protected]>
Reviewed-by: Michel Thierry <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

0 files changed, 0 insertions, 0 deletions