[gsound] build: Additional builddir != srcdir fix

[Tristan Brindle <tbrindle src gnome org>]

commit 4f8a78c6d5bb2a5aa96b140b423a9036768756b6
Author: Yanko Kaneti <yaneti declera com>
Date:   Thu Nov 27 21:33:24 2014 +0200

    build: Additional builddir != srcdir fix
    
    Workaround automake's suboptimal handling of vala compilation
    in the case of builddir != srcdir
    
    https://bugzilla.gnome.org/show_bug.cgi?id=740825

 tools/Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 8736fad..11f8e01 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -8,7 +8,7 @@ bin_PROGRAMS = gsound-play
 gsound_play_SOURCES = gsound-play.vala
 
 gsound_play_VALAFLAGS = \
-    --vapidir ${top_builddir}/gsound \
+    --vapidir ${abs_top_builddir}/gsound \
     --pkg gsound \
     ${NULL}