Need stdlib.h to get NULL on Linux


git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@627 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/tjutil.c b/tjutil.c
index 3d31478..5e22fee 100644
--- a/tjutil.c
+++ b/tjutil.c
@@ -52,6 +52,7 @@
 
 #else
 
+#include <stdlib.h>
 #include <sys/time.h>
 
 double gettime(void)