[babl] Fix another place where assigned_name can be NULL

[Mukund Sivaraman <muks src gnome org>]

commit 38c88fdc0308122fcd0d2bddf841ad83e1e9af97
Author: Mukund Sivaraman <muks banu com>
Date:   Thu Feb 26 20:33:16 2015 +0530

    Fix another place where assigned_name can be NULL

 babl/babl-model.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/babl/babl-model.c b/babl/babl-model.c
index fec5209..dda1cbe 100644
--- a/babl/babl-model.c
+++ b/babl/babl-model.c
@@ -121,7 +121,8 @@ babl_model_new (void *first_argument,
                 if (components >= BABL_MAX_COMPONENTS)
                   {
                     babl_log ("maximum number of components (%i) exceeded for %s",
-                              BABL_MAX_COMPONENTS, assigned_name);
+                              BABL_MAX_COMPONENTS,
+                              assigned_name ? assigned_name : "(unnamed)");
                   }
                 component [components++] = (BablComponent *) bablc;
                 break;