build: avoid "multiply defined..." warning from automake

* Makefile.am (AM_CFLAGS): Add $(WARN_CFLAGS) via +=, not =, to
avoid "multiply defined..." warning from automake.

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 15ec0ea..074cc9c 100644 (file)
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,6 +1,6 @@
 ## Makefile for gnulib/lib                             -*-Makefile-*-
 
-# Copyright (C) 1995-2007 Free Software Foundation, Inc.
+# Copyright (C) 1995-2007, 2009 Free Software Foundation, Inc.
 
 ## This program is free software: you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
 
 include gnulib.mk
 
-AM_CFLAGS = $(WARN_CFLAGS) # $(WERROR_CFLAGS)
+AM_CFLAGS += $(WARN_CFLAGS) # $(WERROR_CFLAGS)
 
 libcoreutils_a_SOURCES += \
   buffer-lcm.c buffer-lcm.h \