[mutter] background-content: ceilf the actor size instead of roundf

[verdre <jonasd src gnome org>]

commit c7a0ab3eb813dd78156434e492f1216766ec6c38
Author: Daniel van Vugt <daniel van vugt canonical com>
Date:   Tue Oct 27 16:54:50 2020 +0800

    background-content: ceilf the actor size instead of roundf
    
    We want the bounding box so `ceilf` seems more appropriate. It was
    only written using `roundf` before as a workaround for inaccuracies
    coming out of `clutter_actor_get_transformed_size` that would have
    tricked `ceilf` into landing on the wrong integer. But that's since
    been fixed by 67cc60cbda so we can use `ceilf` now.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1532

 src/compositor/meta-background-content.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/compositor/meta-background-content.c b/src/compositor/meta-background-content.c
index 7990ad47b5..b2da6b03f8 100644
--- a/src/compositor/meta-background-content.c
+++ b/src/compositor/meta-background-content.c
@@ -532,8 +532,8 @@ meta_background_content_paint_content (ClutterContent      *content,
       clutter_actor_get_transformed_size (actor,
                                           &transformed_width,
                                           &transformed_height);
-      rect_within_stage.width = roundf (transformed_width);
-      rect_within_stage.height = roundf (transformed_height);
+      rect_within_stage.width = ceilf (transformed_width);
+      rect_within_stage.height = ceilf (transformed_height);
 
       untransformed =
         rect_within_actor.x == rect_within_stage.x &&