[libgsystem] Force embedders to define source path

[Colin Walters <walters src gnome org>]

commit ccf0438a8fa47e7fa1cf5e87c41896f29b81b276
Author: Colin Walters <walters verbum org>
Date:   Sun Jul 15 11:50:57 2012 -0400

    Force embedders to define source path
    
    Trying to use ?= apparently confuses automake.

 Makefile-libgsystem.am |   10 +++-------
 gsystem-local-alloc.c  |    2 +-
 2 files changed, 4 insertions(+), 8 deletions(-)
---
diff --git a/Makefile-libgsystem.am b/Makefile-libgsystem.am
index 92579bc..fb09b51 100644
--- a/Makefile-libgsystem.am
+++ b/Makefile-libgsystem.am
@@ -15,16 +15,12 @@
 # Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 # Boston, MA 02111-1307, USA.
 
-libgsystem_src_dir ?= src/libgsystem
-libgsystem_cflags ?= $(GIO_UNIX_CFLAGS)
-libgsystem_libs ?= $(GIO_UNIX_LIBS)
-
 noinst_LTLIBRARIES += libgsystem.la
 
 libgsystem_la_SOURCES = \
-	$(libgsystem_src_dir)/gsystem-local-alloc.h \
-	$(libgsystem_src_dir)/gsystem-local-alloc.c \
-	$(libgsystem_src_dir)/libgsystem.h \
+	$(libgsystem_srcpath)/gsystem-local-alloc.h \
+	$(libgsystem_srcpath)/gsystem-local-alloc.c \
+	$(libgsystem_srcpath)/libgsystem.h \
 	$(NULL)
 
 libgsystem_la_CFLAGS = $(AM_CFLAGS) $(libgsystem_cflags)
diff --git a/gsystem-local-alloc.c b/gsystem-local-alloc.c
index 36e722c..1bbea90 100644
--- a/gsystem-local-alloc.c
+++ b/gsystem-local-alloc.c
@@ -20,7 +20,7 @@
 
 #include "config.h"
 
-#include "gs-local-alloc.h"
+#include "gsystem-local-alloc.h"
 
 void
 gs_local_free (void *loc)