[gnome-shell] blur-effect: Use int for opacity override

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 46f94241eb6f076a637623a0905a373019b56ce1
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Fri Feb 7 10:08:13 2020 +0100

    blur-effect: Use int for opacity override
    
    The opacity override can be -1 if no override is set, so use the
    appropriate datatype here.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/991

 src/shell-blur-effect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/shell-blur-effect.c b/src/shell-blur-effect.c
index e40bb542a2..0022327467 100644
--- a/src/shell-blur-effect.c
+++ b/src/shell-blur-effect.c
@@ -158,7 +158,7 @@ struct _ShellBlurEffect
   ClutterEffect parent_instance;
 
   ClutterActor *actor;
-  uint8_t old_opacity_override;
+  int old_opacity_override;
 
   BlurData blur[2];