venus: destroy a device's object mutex after the objects that lock it

From BattleTempest's DroidDeck-Pixel (kevinbryant551-ux/DroidDeck-Pixel, GPL-3.0),
tools/venus/patches/0103-destroy-object-mutex-after-objects.patch. Bionic aborts on locking a
destroyed mutex ("pthread_mutex_lock called on a destroyed mutex", seen on a Tab S9 FE G68
and a Pixel 9a), so a client that exited holding objects took the render worker down.

diff --git a/src/venus/vkr_device.c b/src/venus/vkr_device.c
index 9144180..7b7c904 100644
--- a/src/venus/vkr_device.c
+++ b/src/venus/vkr_device.c
@@ -324,13 +324,16 @@ vkr_device_destroy(struct vkr_context *ctx, struct vkr_device *dev, bool destroy
          vkr_log("vkDeviceWaitIdle(%p) failed(%d)", dev, (int32_t)result);
    }
 
-   mtx_destroy(&dev->object_mutex);
-
+   /* The leftover objects are removed under object_mutex: destroy it after them. glibc lets a
+    * destroyed mutex be locked; bionic aborts ("pthread_mutex_lock called on a destroyed mutex"),
+    * so every client that exited holding objects took its render worker down. */
    if (!list_is_empty(&dev->objects)) {
       list_for_each_entry_safe (struct vkr_object, obj, &dev->objects, track_head)
          vkr_device_object_destroy(ctx, dev, obj);
    }
 
+   mtx_destroy(&dev->object_mutex);
+
    list_for_each_entry_safe (struct vkr_queue, queue, &dev->queues, base.track_head)
       vkr_queue_destroy(ctx, queue);