[gtk/wip/matthiasc/lottie-stroke: 205/217] Fix a compiler warning

[Matthias Clasen <matthiasc src gnome org>]

commit 16ac1200f01f885e11b6ed5321e726fcb1c9ab11
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Dec 3 23:22:25 2020 -0500

    Fix a compiler warning
    
    Initializing length was lost in 666dbec38342b57594d37138.

 gtk/gtkrenderborder.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtkrenderborder.c b/gtk/gtkrenderborder.c
index af04f1a8bf..3a273ffcfb 100644
--- a/gtk/gtkrenderborder.c
+++ b/gtk/gtkrenderborder.c
@@ -436,7 +436,7 @@ snapshot_frame_stroke (GtkSnapshot          *snapshot,
       border_width[0] == border_width[3] &&
       hidden_side == 0)
     {
-      double length;
+      double length = 0;
 
       /* FAST PATH:
        * Mostly expected to trigger for focus rectangles */