[gtk] gl renderer: Sprinkle some const around

[Timm Bäder <baedert src gnome org>]

commit 76795ffba963478f1d139314871b48375d8b7e07
Author: Timm Bäder <mail baedert org>
Date:   Mon Dec 30 12:59:01 2019 +0100

    gl renderer: Sprinkle some const around

 gsk/gl/gskglrenderer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gsk/gl/gskglrenderer.c b/gsk/gl/gskglrenderer.c
index 4d0699eed4..157d827658 100644
--- a/gsk/gl/gskglrenderer.c
+++ b/gsk/gl/gskglrenderer.c
@@ -665,10 +665,10 @@ render_text_node (GskGLRenderer   *self,
   const float text_scale = ops_get_scale (builder);
   const graphene_point_t *offset = gsk_text_node_get_offset (node);
   const guint num_glyphs = gsk_text_node_get_num_glyphs (node);
+  const float x = offset->x + builder->dx;
+  const float y = offset->y + builder->dy;
   int i;
   int x_position = 0;
-  float x = offset->x + builder->dx;
-  float y = offset->y + builder->dy;
   GlyphCacheKey lookup;
 
   /* If the font has color glyphs, we don't need to recolor anything */