drm/syncobj: Tune down unordered timeline DRM_ERROR

Userspace can provoke this, we generally don't allow userspace to spam
dmesg. Tune it down to debug. Unfortunately we don't have easy access
to the drm_device here (not at all without changing a few things), so
leave it as old style dmesg output for now.

References: https://patchwork.freedesktop.org/series/80146/
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: "Christian König" <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200801092625.1107609-1-daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_syncobj.c

@@ -297,7 +297,7 @@ void drm_syncobj_add_point(struct drm_syncobj *syncobj,
 	prev = drm_syncobj_fence_get(syncobj);
 	/* You are adding an unorder point to timeline, which could cause payload returned from query_ioctl is 0! */
 	if (prev && prev->seqno >= point)
-		DRM_ERROR("You are adding an unorder point to timeline!\n");
+		DRM_DEBUG("You are adding an unorder point to timeline!\n");
 	dma_fence_chain_init(chain, prev, fence, point);
 	rcu_assign_pointer(syncobj->fence, &chain->base);