renderonly: close the gpu fd when destroying renderonly

Currently the screen destruction closes the dup'ed fd, but not the
original renderonly gpu fd, which is kept around for the lifetime of
the renderonly.

Squashed revert of "vc4: Don't leak the GPU fd for renderonly usage."
(commit 99ef66c325) as requested by Eric.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6983>

src/gallium/winsys/kmsro/drm/kmsro_drm_winsys.c

@@ -40,6 +40,9 @@
 
 static void kmsro_ro_destroy(struct renderonly *ro)
 {
+   if (ro->gpu_fd >= 0)
+      close(ro->gpu_fd);
+
    FREE(ro);
 }
 

src/gallium/winsys/vc4/drm/vc4_drm_winsys.c

@@ -61,5 +61,5 @@ struct pipe_screen *
 vc4_drm_screen_create_renderonly(struct renderonly *ro,
                                  const struct pipe_screen_config *config)
 {
-   return vc4_screen_create(ro->gpu_fd, ro);
+   return vc4_screen_create(fcntl(ro->gpu_fd, F_DUPFD_CLOEXEC, 3), ro);
 }