[babl] Remove useless join_paths arg

[Øyvind Kolås <ok src gnome org>]

commit eed7c47e72a4d7c76c1c2f60476f7dbc0891e0cc
Author: Félix Piédallu <felix piedallu me>
Date:   Wed Dec 6 15:22:41 2017 +0100

    Remove useless join_paths arg

 meson.build |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)
---
diff --git a/meson.build b/meson.build
index 3ea038d..9d330ed 100644
--- a/meson.build
+++ b/meson.build
@@ -240,9 +240,7 @@ configure_file(
 # Subdirs
 
 rootInclude = include_directories('.')
-version_script = join_paths(
-  meson.source_root(), meson.current_source_dir(), 'babl.map'
-)
+version_script = join_paths(meson.current_source_dir(), 'babl.map')
 
 subdir('babl')
 subdir('extensions')