[babl] tests: output with more details when grayscale_to_rgb fails

[Téo Mazars <teom src gnome org>]

commit 2c07b091b6037b980484d9a16a0f9d8aaf0cb912
Author: Téo Mazars <teo mazars ensimag fr>
Date:   Sun Aug 4 20:14:31 2013 +0200

    tests: output with more details when grayscale_to_rgb fails

 tests/grayscale_to_rgb.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/tests/grayscale_to_rgb.c b/tests/grayscale_to_rgb.c
index 6658f7f..7da0c86 100644
--- a/tests/grayscale_to_rgb.c
+++ b/tests/grayscale_to_rgb.c
@@ -61,7 +61,8 @@ test (void)
     {
       if (rgb_buf[i] != rgb_buf_ref[i])
         {
-          babl_log ("index %i is problematic", i);
+          babl_log ("index %i is problematic : %f instead of %f",
+                    i, rgb_buf[i], rgb_buf_ref[i]);
           OK = 0;
         }
     }