[gegl] gegl-cache: fix out of bounds access

[Øyvind Kolås <ok src gnome org>]

commit c4645e7fe717dafdc9074239a066aeca78c0f674
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Sep 16 21:23:53 2015 +0200

    gegl-cache: fix out of bounds access
    
    As detected by cpppcheck reported by serval2412 yahoo fr in bug #75458

 gegl/buffer/gegl-cache.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gegl/buffer/gegl-cache.c b/gegl/buffer/gegl-cache.c
index 79ce88b..47cde7f 100644
--- a/gegl/buffer/gegl-cache.c
+++ b/gegl/buffer/gegl-cache.c
@@ -301,7 +301,7 @@ gegl_cache_computed (GeglCache           *self,
 
   g_mutex_lock (&self->mutex);
 
-  if (level <= GEGL_CACHE_VALID_MIPMAPS)
+  if (level < GEGL_CACHE_VALID_MIPMAPS)
     gegl_region_union_with_rect (self->valid_region[level], rect);
 
   g_signal_emit (self, gegl_cache_signals[COMPUTED], 0, rect, NULL);