[master] 3b40a01 Fix build

[Federico G. Schwindt]

commit 3b40a0163156c4e3ccac1b785da80713cb30ee95
Author: Federico G. Schwindt <fgsch at lodoss.net>
Date:   Mon Sep 12 11:33:53 2016 +0100

    Fix build

diff --git a/bin/varnishtest/vtc_main.c b/bin/varnishtest/vtc_main.c
index ce547ae..4492b36 100644
--- a/bin/varnishtest/vtc_main.c
+++ b/bin/varnishtest/vtc_main.c
@@ -402,7 +402,7 @@ i_mode(void)
 	/*
 	 * strict jemalloc checking
 	 */
-	AZ(putenv("MALLOC_CONF=abort:true,redzone:true,junk:true"));
+	AZ(putenv((char *)"MALLOC_CONF=abort:true,redzone:true,junk:true"));
 }
 
 /**********************************************************************