Fix configure test for PBKDF2 in nettle

On my Debian jessie system, including nettle/pbkdf2.h does not cause
NULL to be defined, which causes the test to fail to compile.  Include
stddef.h to bring in a definition of NULL.

Cc: qemu-trivial@nongnu.org
Cc: qemu-stable@nongnu.org
Signed-off-by: Steven Luo <steven+qemu@steven676.net>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(cherry picked from commit 9e87a691bd46846e2232f8c30605c491c85ac987)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/configure b/configure
index 49bdb4bde69c0fc16e1791bf8600bd95302d8348..60e3c0dd6db681e4c3d017dab0ccce45a1adbd88 100755 (executable)
--- a/configure
+++ b/configure
@@ -2342,6 +2342,7 @@ if test "$nettle" != "no"; then
         nettle="yes"
 
         cat > $TMPC << EOF
+#include <stddef.h>
 #include <nettle/pbkdf2.h>
 int main(void) {
      pbkdf2_hmac_sha256(8, NULL, 1000, 8, NULL, 8, NULL);