Update to upstream openafs security release 1.6.13

OPENAFS-SA-2015-001 - vos leaks stack data onto the wire in the clear
when creating vldb entries

OPENAFS-SA-2015-002 - bos commands can be spoofed, including some
which alter server state

OPENAFS-SA-2015-003 - pioctls leak kernel memory contents

OPENAFS-SA-2015-004 - kernel pioctl support for OSD command passing can
trigger a panic

OPENAFS-SA-2015-006 - Buffer overflow in OpenAFS vlserver

Approved by: delphij (ports committer)
MFH: 2015Q3
Security: CVE-2015-3282, CVE-2015-3283, CVE-2015-3284, CVE-2015-3285