[gxml] meson: added sourcedir to be used as subproject

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit ec7499ea084d34a36212d1b1b8fcdf1f2e91e3b2
Author: Daniel Espinosa <esodan gmail com>
Date:   Tue Jul 2 18:54:27 2019 -0500

    meson: added sourcedir to be used as subproject

 gxml/meson.build | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/gxml/meson.build b/gxml/meson.build
index 2327fa9..1d37f45 100644
--- a/gxml/meson.build
+++ b/gxml/meson.build
@@ -189,7 +189,8 @@ custom_target('typelib',
 endif
 endif
 
-libxml_build_dir = meson.current_build_dir ()
+libgxml_build_dir = meson.current_build_dir ()
+libgxml_src_dir = meson.current_source_dir ()
 libgxml_dep = declare_dependency(include_directories : inc_rooth,
   link_with : libgxml,
   dependencies: libgxml_deps,