[OpenAFS] some older openafs-client versions have started failing

[Chad William Seys]

Hi all,
   I found the break point in when openafs starts having problems with 
git checkout on my test repo:

First broken: 3.16.7-ckt25-1        (compiled 2016-03-06)
Last working: 3.16.7-ckt20-1+deb8u4

Here is a changelog in case someone knows what to hunt for in:
http://metadata.ftp-master.debian.org/changelogs//main/l/linux/linux_3.16.7-ckt25-2_changelog

Thanks!
Chad.