aux/tc: fix renderpass splitting on flush

it's expected that a driver won't immediately trigger a deferred flush
if a fence is present, so don't split the renderpass in this case since
that breaks everything

Fixes: 07017aa137 ("util/tc: implement renderpass tracking")

Acked-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21800>

src/gallium/auxiliary/util/u_threaded_context.c

@@ -3437,7 +3437,8 @@ tc_flush(struct pipe_context *_pipe, struct pipe_fence_handle **fence,
    bool async = flags & (PIPE_FLUSH_DEFERRED | PIPE_FLUSH_ASYNC);
    bool deferred = (flags & PIPE_FLUSH_DEFERRED) > 0;
 
-   tc->in_renderpass = false;
+   if (!deferred || !fence)
+      tc->in_renderpass = false;
 
    if (async && tc->options.create_fence) {
       if (fence) {