[4.1] aad2aaa WS_Printf() can also overflow the workspace.

[Lasse Karstensen]

commit aad2aaaeadccc6844c5d1c9c80354193fa7180be
Author: Lasse Karstensen <lkarsten at varnish-software.com>
Date:   Mon Sep 28 17:04:47 2015 +0200

    WS_Printf() can also overflow the workspace.

diff --git a/bin/varnishd/cache/cache_ws.c b/bin/varnishd/cache/cache_ws.c
index 60fdd44..7070f1a 100644
--- a/bin/varnishd/cache/cache_ws.c
+++ b/bin/varnishd/cache/cache_ws.c
@@ -187,6 +187,7 @@ WS_Printf(struct ws *ws, const char *fmt, ...)
 	va_end(ap);
 	if (v >= u) {
 		WS_Release(ws, 0);
+		WS_MarkOverflow(ws);
 		p = NULL;
 	} else {
 		WS_Release(ws, v + 1);