drm/msm/a6xx: Remove state objects from list before freeing

Technically it worked as it was before, only because it was using the
_safe version of the iterator.  But it is sloppy practice to leave
dangling pointers.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/507017/
Link: https://lore.kernel.org/r/20221013225520.371226-4-robdclark@gmail.com

drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c

@@ -1046,8 +1046,10 @@ static void a6xx_gpu_state_destroy(struct kref *kref)
 	if (a6xx_state->gmu_debug)
 		kvfree(a6xx_state->gmu_debug->data);
 
-	list_for_each_entry_safe(obj, tmp, &a6xx_state->objs, node)
+	list_for_each_entry_safe(obj, tmp, &a6xx_state->objs, node) {
+		list_del(&obj->node);
 		kvfree(obj);
+	}
 
 	adreno_gpu_state_destroy(state);
 	kfree(a6xx_state);