[babl] Fix warning: comparison of integer expressions of different signedness: ‘int’ and ‘long unsigned int

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 0cfa2ed067081de20984b69d321e14e638b931cf
Author: Axel Viala <axel viala darnuria eu>
Date:   Thu Mar 24 17:01:01 2022 +0100

    Fix warning: comparison of integer expressions of different signedness: ‘int’ and ‘long unsigned int’ 
[-Wsign-compare]

 babl/base/formats.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/babl/base/formats.c b/babl/base/formats.c
index bbdedf347..03488c412 100644
--- a/babl/base/formats.c
+++ b/babl/base/formats.c
@@ -35,7 +35,7 @@ BABL_SIMD_SUFFIX (babl_formats_init) (void)
     babl_type_from_id (BABL_U16),
     babl_type_from_id (BABL_U32)
   };
-  for (int i = 0; i < sizeof (types)/sizeof(types[0]);i++)
+  for (size_t i = 0; i < sizeof (types) / sizeof(types[0]); i++)
   {
     const Babl *type = types[i];