[gsound] build: Fix builddir != srcdir -> distcheck

[Tristan Brindle <tbrindle src gnome org>]

commit ebc8e20115c1fba6320c7c1e5ec6a988d2bac624
Author: Yanko Kaneti <yaneti declera com>
Date:   Wed Nov 26 12:22:58 2014 +0200

    build: Fix builddir != srcdir -> distcheck
    
    gsound.h is not a product of the build so use it from top_srcdir

 tools/Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 9b720f8..8736fad 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -13,7 +13,7 @@ gsound_play_VALAFLAGS = \
     ${NULL}
 
 gsound_play_CPPFLAGS = \
-    -I${top_builddir}/gsound \
+    -I${top_srcdir}/gsound \
     ${GSOUND_CFLAGS} \
     ${NULL}