[gnome-themes-standard] one more legibility @if fix

[Jakub Steiner <jimmac src gnome org>]

commit 7ea8886bd55e21e8792ac1e0a2ab19764611761d
Author: Jakub Steiner <jimmac gmail com>
Date:   Tue May 27 12:14:02 2014 +0200

    one more legibility @if fix

 themes/Adwaita/gtk-3.0/_drawing.scss |   12 ++----------
 1 files changed, 2 insertions(+), 10 deletions(-)
---
diff --git a/themes/Adwaita/gtk-3.0/_drawing.scss b/themes/Adwaita/gtk-3.0/_drawing.scss
index 31bf1e1..a758bf0 100644
--- a/themes/Adwaita/gtk-3.0/_drawing.scss
+++ b/themes/Adwaita/gtk-3.0/_drawing.scss
@@ -6,16 +6,8 @@ $widget_bottom_hilight: 0 1px $borders_edge; //outer hilight "used" on
                                              //most widgets, FIXME 1px
 // buttons
 
- mixin _button_border_color ($c) {
-//
-// helper function to draw borders
-//
-  @if $variant=='light' {
-    border-color: darken($c,30%);
-  }
-  @else {
-    border-color: darken($c,10%);
-  }
+ mixin _button_border_color ($c) { // helper function to draw borders
+  border-color: if($variant=='light', darken($c,30%), darken($c,10%));
 }
 
 @mixin _button_text_shadow ($tc:$fg_color, $bg:$bg_color) {