[babl] tools: babl-icc-rewrite; abort with error message instead of segfault

[Øyvind Kolås <ok src gnome org>]

commit f9728d71db3bbb8beedfd0edb91466439120b66e
Author: Øyvind Kolås <pippin gimp org>
Date:   Sat Sep 2 15:32:23 2017 +0200

    tools: babl-icc-rewrite; abort with error message instead of segfault

 tools/babl-icc-rewrite.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/tools/babl-icc-rewrite.c b/tools/babl-icc-rewrite.c
index bf18bc7..bb1bc64 100644
--- a/tools/babl-icc-rewrite.c
+++ b/tools/babl-icc-rewrite.c
@@ -49,6 +49,11 @@ main (int    argc,
 
   babl = babl_space_from_icc (icc_data, icc_len, &error);
   free (icc_data);
+  if (error || !babl)
+  {
+    fprintf (stderr, "%s error %s", argv[0], error);
+    return -1;
+  }
 
   icc_data = (char *)babl_space_to_icc (babl, &genlen);
   if (icc_data)