[mutter] theme: Scale titlebar spacing when computing x

[Marco Trevisan <marcotrevi src gnome org>]

commit deda7a52355566723b45dad3d18108d326c06633
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Fri Mar 23 10:50:04 2018 -0500

    theme: Scale titlebar spacing when computing x
    
    The value is not scaled by default so it needs to be adjusted
    depending on the window scaling, as it's done in other places.
    
    Fixes: #87

 src/ui/theme.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/ui/theme.c b/src/ui/theme.c
index 8786b17f3..b909d9b6a 100644
--- a/src/ui/theme.c
+++ b/src/ui/theme.c
@@ -580,7 +580,7 @@ meta_frame_layout_calc_geometry (MetaFrameLayout        *layout,
       x = rect->visible.x - layout->button_margin.left * scale;
 
       if (i > 0)
-        x -= layout->titlebar_spacing;
+        x -= layout->titlebar_spacing * scale;
 
       --i;
     }