zink: Make sparse always wait on pending gfx commands

We need to make sure that earlier gfx commands don't see the committed
resource. Also, the commit doesn't necessarily happen atomically,
because the kernel has to unmap the NULL page and then map the BO page,
so earlier gfx submits could race with the kernel an see an unmapped
page and fault. This is the same race when uncommitting but in reverse.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37065>

src/gallium/drivers/zink/zink_bo.c

@@ -777,8 +777,8 @@ init_timeline_wait(struct zink_context *ctx, struct zink_resource *res, bool com
    if (*wait)
       return timeline;
 
-   /* commit || no usage = no wait */
-   if (commit || !zink_resource_has_usage(res) || zink_resource_usage_check_completion_fast(screen, res, ZINK_RESOURCE_ACCESS_RW))
+   /* no usage = no wait */
+   if (!zink_resource_has_usage(res) || zink_resource_usage_check_completion_fast(screen, res, ZINK_RESOURCE_ACCESS_RW))
       return timeline;
 
    if (zink_resource_usage_is_unflushed(res) && !zink_resource_usage_matches(res, ctx->bs)) {