Adds explicit include to stdlib.h for abort
diff --git a/programs/fuzz/fuzz_privkey.c b/programs/fuzz/fuzz_privkey.c
index ce5e7c4..178d17b 100644
--- a/programs/fuzz/fuzz_privkey.c
+++ b/programs/fuzz/fuzz_privkey.c
@@ -1,4 +1,5 @@
 #include <stdint.h>
+#include <stdlib.h>
 #include "mbedtls/pk.h"
 
 //4 Kb should be enough for every bug ;-)