The correct return value when we reach the end is -1, not 0.

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@2862 d4fa192b-c00b-0410-8231-f00ffab90ce4

lib/libvarnishapi/shmlog.c

@@ -300,7 +300,7 @@ VSL_NextLog(struct VSL_data *vd, unsigned char **pp)
 			continue;
 		} else if (vd->keep) {
 			if (--vd->keep == 0)
-				return (0);
+				return (-1);
 		}
 		if (vd->map[p[SHMLOG_TAG]] & M_SELECT) {
 			*pp = p;