i915g: Enable reuse of buffers

src/gallium/winsys/drm/intel/gem/intel_drm_api.c

@@ -167,6 +167,7 @@ intel_drm_create_screen(struct drm_api *api, int drmFD,
    idws->base.destroy = intel_drm_winsys_destroy;
 
    idws->pools.gem = drm_intel_bufmgr_gem_init(idws->fd, idws->max_batch_size);
+   drm_intel_bufmgr_gem_enable_reuse(idws->pools.gem);
 
    idws->softpipe = FALSE;
    idws->dump_cmd = debug_get_bool_option("INTEL_DUMP_CMD", FALSE);