virglrenderer.c: Fix warning

virglrenderer.c: In Funktion »virgl_renderer_cleanup«:
virglrenderer.c:272:35: Warnung: unused parameter »cookie« [-Wunused-
parameter]
 void virgl_renderer_cleanup(void *cookie)

v2: Use mesa-style UNUSED for unused parameters

Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Signed-off-by: Jakob Bornecrantz <jakob@collabora.com>

src/virglrenderer.c

@@ -269,7 +269,7 @@ void virgl_renderer_poll(void)
    vrend_renderer_check_fences();
 }
 
-void virgl_renderer_cleanup(void *cookie)
+void virgl_renderer_cleanup(UNUSED void *cookie)
 {
    vrend_renderer_fini();
 #ifdef HAVE_EPOXY_EGL_H