configure: fix gpac detection with -Wp,-D_FORTIFY_SOURCE=2

diff --git a/configure b/configure
index 250b0ace70cb8760957c46220dac063942fea1d5..6b2d616c4a6bfc6239ba1686e6efe7d7bfd576da 100755 (executable)
--- a/configure
+++ b/configure
@@ -904,7 +904,7 @@ if [ "$gpac" = "auto" ] ; then
 fi
 if [ "$gpac" = "yes" ] ; then
     define HAVE_GPAC
-    if cc_check gpac/isomedia.h "-Werror $GPAC_LIBS" "gf_malloc(1); gf_free(NULL);" ; then
+    if cc_check gpac/isomedia.h "-Werror $GPAC_LIBS" "void *p; p = gf_malloc(1); gf_free(p);" ; then
         define HAVE_GF_MALLOC
     fi
     LDFLAGSCLI="$GPAC_LIBS $LDFLAGSCLI"