[babl] meson: fix typoed filename

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

commit a4e8d2119f1233eb66e4cc4d60285d97112767e4
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Jun 19 23:41:51 2019 +0200

    meson: fix typoed filename

 tests/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tests/meson.build b/tests/meson.build
index 2ab0381..dfe7d45 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -21,7 +21,7 @@ test_names = [
   'sanity',
   'srgb_to_lab_u8',
   'transparent',
-  'alpha_symmeric_transform',
+  'alpha_symmetric_transform',
   'types',
 ]
 if platform_unix