[vte] build: Fix double defines of *CLEANFILES

[Christian Persch <chpe src gnome org>]

commit 64f7ae57e8cd6667dc9fc7afd870df6c67cf87c7
Author: Christian Persch <chpe gnome org>
Date:   Sun May 18 11:19:52 2014 +0200

    build: Fix double defines of *CLEANFILES

 src/Makefile.am |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index 2f4ceec..57d7204 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -138,9 +138,9 @@ libvte_ VTE_API_MAJOR_VERSION@_ VTE_API_MINOR_VERSION@_la_LIBADD = \
 
 VTESEQ_BUILTSOURCES = vteseq-list.h vteseq-2.c vteseq-n.c
 BUILT_SOURCES = box_drawing.h marshal.c marshal.h vtetypebuiltins.c vtetypebuiltins.h vteresources.c 
$(VTESEQ_BUILTSOURCES)
-MAINTAINERCLEANFILES = $(VTESEQ_BUILTSOURCES)
+MAINTAINERCLEANFILES += $(VTESEQ_BUILTSOURCES)
 EXTRA_DIST += $(VTESEQ_BUILTSOURCES) box_drawing.txt box_drawing_generate.sh iso2022.txt vtetivars.awk
-CLEANFILES = box_drawing.h marshal.c marshal.h vtetypebuiltins.c vtetypebuiltins.h stamp-vtetypebuiltins.h 
vteresources.c
+CLEANFILES += box_drawing.h marshal.c marshal.h vtetypebuiltins.c vtetypebuiltins.h stamp-vtetypebuiltins.h 
vteresources.c
 
 box_drawing.h: box_drawing.txt
        $(AM_V_GEN) $(srcdir)/box_drawing_generate.sh < $< > $@