[gnome-robots] build: Fix srcdir != builddir build

[Ting-Wei Lan <lantw src gnome org>]

commit e3415a18f9c3521413138b291ea0a21e2318bc47
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Thu Jul 14 02:56:10 2016 +0800

    build: Fix srcdir != builddir build
    
    https://bugzilla.gnome.org/show_bug.cgi?id=768786

 src/Makefile.am |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index 8251b3d..7aabe40 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -39,8 +39,8 @@ gnome_robots_SOURCES = \
 
 BUILT_SOURCES = robots-resources.c
 
-robots-resources.c: $(shell $(GLIB_COMPILE_RESOURCES) --generate-dependencies robots.gresource.xml)
-       $(AM_V_GEN) $(GLIB_COMPILE_RESOURCES) --target=$@ --sourcedir=$(srcdir) --generate-source 
robots.gresource.xml
+robots-resources.c: $(shell $(GLIB_COMPILE_RESOURCES) --generate-dependencies ${srcdir}/robots.gresource.xml)
+       $(AM_V_GEN) $(GLIB_COMPILE_RESOURCES) --target=$@ --sourcedir=$(srcdir) --generate-source 
$(srcdir)/robots.gresource.xml
 
 gnome_robots_CPPFLAGS = \
        -I$(top_srcdir) \