zink: avoid replacing valid tcs with injected one

need to check both arrays here since we only want to use an injected shader
if we don't have a real one, not just if the real one isn't being updated

Fixes: 334759d8

 ("zink: implement passthrough tcs shader injection")
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <mesa/mesa!8271>

src/gallium/drivers/zink/zink_program.c

@@ -319,7 +319,8 @@ update_shader_modules(struct zink_context *ctx, struct zink_shader *stages[ZINK_
       dirty[tgsi_processor_to_shader_stage(type)] = stages[type];
    }
    if (ctx->dirty_shader_stages & (1 << PIPE_SHADER_TESS_EVAL)) {
-      if (dirty[MESA_SHADER_TESS_EVAL] && !dirty[MESA_SHADER_TESS_CTRL]) {
+      if (dirty[MESA_SHADER_TESS_EVAL] && !dirty[MESA_SHADER_TESS_CTRL] &&
+          !stages[PIPE_SHADER_TESS_CTRL]) {
          dirty[MESA_SHADER_TESS_CTRL] = stages[PIPE_SHADER_TESS_CTRL] = zink_shader_tcs_create(ctx, stages[PIPE_SHADER_VERTEX]);
          dirty[MESA_SHADER_TESS_EVAL]->generated = stages[PIPE_SHADER_TESS_CTRL];
       }