Fix "_FORTIFY_SOURCE" redefined warning

On Ubuntu 12.04, we got the following warning message:
<command-line>:0:0: warning: "_FORTIFY_SOURCE" redefined
 [enabled by default]
<built-in>:0:0: note: this is the location of the previous definition

This was already fixed in VP8 configure file. Did the same change in
experimental branch to stop this warning.

Change-Id: Id162e5fd8841585ae806df6560b2f7536ea307c0

diff --git a/build/make/configure.sh b/build/make/configure.sh
index 9bff9cb224097f2eb4c4634c9ec5bb8f12346514..00c27c261abb4d18debf317ac88472bef3a14178 100755 (executable)
--- a/build/make/configure.sh
+++ b/build/make/configure.sh
@@ -974,7 +974,7 @@ process_common_toolchain() {
 
     # Work around longjmp interception on glibc >= 2.11, to improve binary
     # compatibility. See http://code.google.com/p/webm/issues/detail?id=166
-    enabled linux && check_add_cflags -D_FORTIFY_SOURCE=0
+    enabled linux && check_add_cflags -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
 
     # Check for strip utility variant
     ${STRIP} -V 2>/dev/null | grep GNU >/dev/null && enable gnu_strip