[4.1] fef00c4 SmartOS needs stdlib.h for closefrom()

[Lasse Karstensen]

commit fef00c4c1f98088bac2abaf3042bcae655ceb31c
Author: Federico G. Schwindt <fgsch at lodoss.net>
Date:   Wed Jan 6 16:49:11 2016 +0000

    SmartOS needs stdlib.h for closefrom()

diff --git a/lib/libvarnish/vsub.c b/lib/libvarnish/vsub.c
index d774e53..a7c658c 100644
--- a/lib/libvarnish/vsub.c
+++ b/lib/libvarnish/vsub.c
@@ -36,6 +36,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>