[gtk] animatedstyle: Fix the debug build

[Matthias Clasen <matthiasc src gnome org>]

commit 5e95e15a0329e42357cb864048d1529766749d82
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Jan 29 14:02:30 2020 +0100

    animatedstyle: Fix the debug build
    
    This wasn't caught by our ci.

 gtk/gtkcssanimatedstyle.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtkcssanimatedstyle.c b/gtk/gtkcssanimatedstyle.c
index 0012a93422..2070e7f7a6 100644
--- a/gtk/gtkcssanimatedstyle.c
+++ b/gtk/gtkcssanimatedstyle.c
@@ -932,7 +932,7 @@ gtk_css_animated_style_new_advance (GtkCssAnimatedStyle *source,
   guint i;
 
   gtk_internal_return_val_if_fail (GTK_IS_CSS_ANIMATED_STYLE (source), NULL);
-  gtk_internal_return_val_if_fail (GTK_IS_CSS_STYLE (base), NULL);
+  gtk_internal_return_val_if_fail (GTK_IS_CSS_STYLE (base_style), NULL);
 
   if (timestamp == 0 || timestamp == source->current_time)
     return g_object_ref (source->style);