Fix build out of tree

Bug 14542

glib-compile-resource needs to be told where to find its resources when
building out of tree.

settings-dialogs/Makefile.am

@@ -106,10 +106,10 @@ xfwm4-tweaks-dialog_ui.h: xfwm4-tweaks-dialog.glade
 	$(AM_V_GEN) exo-csource --static --strip-comments --strip-content --name=tweaks_dialog_ui $< >$@
 
 workspace-resource.h:
-	$(AM_V_GEN) $(GLIB_COMPILE_RESOURCES) $(srcdir)/workspace.gresource.xml --target=$@ --generate-header
+	$(AM_V_GEN) $(GLIB_COMPILE_RESOURCES) --sourcedir=$(srcdir) $(srcdir)/workspace.gresource.xml --target=$@ --generate-header
 
 workspace-resource.c:
-	$(AM_V_GEN) $(GLIB_COMPILE_RESOURCES) $(srcdir)/workspace.gresource.xml --target=$@ --generate-source
+	$(AM_V_GEN) $(GLIB_COMPILE_RESOURCES) --sourcedir=$(srcdir) $(srcdir)/workspace.gresource.xml --target=$@ --generate-source
 
 endif