aux/trace: clean up some zink+lavapipe tracing awfulness

now that it's easier to determine whether zink is being used (mostly),
this whole thing can be simplified

Reviewed-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15857>

src/gallium/auxiliary/driver_trace/tr_screen.c

@@ -1264,7 +1264,6 @@ trace_screen_create(struct pipe_screen *screen)
 {
    struct trace_screen *tr_scr;
 
-#ifdef ZINK_WITH_SWRAST_VK
    /* if zink+lavapipe is enabled, ensure that only one driver is traced */
    const char *driver = debug_get_option("MESA_LOADER_DRIVER_OVERRIDE", NULL);
    if (driver && !strcmp(driver, "zink")) {
@@ -1280,7 +1279,7 @@ trace_screen_create(struct pipe_screen *screen)
             return screen;
       }
    }
-#endif
+
    if (!trace_enabled())
       goto error1;
 

src/gallium/auxiliary/meson.build

@@ -515,9 +515,6 @@ idep_u_tracepoints = declare_dependency(
 )
 
 libgallium_extra_c_args = []
-if with_swrast_vk and with_gallium_zink
-  libgallium_extra_c_args += '-DZINK_WITH_SWRAST_VK'
-endif
 libgallium = static_library(
   'gallium',
   [files_libgallium],