Add smb2.session.reauth4 to flapping list for XFS and CephFS(kclient)

[anoopcs9]

With recent changes to smb.conf, smb2.session.reauth4 is expected to fail on XFS and CephFS kclient method. You can find more details from samba-in-kubernetes/sit-environment#109 (comment).

Also remember that this is not a problem with CephFS vfs approach but our clone of selftest mechanism currently lacks the ability to consider flapping lists based on variants for a particular backend.

[spuiuk]

We could use "cephfs-vfs"(or any other variation) as a new filesystem.
The cost is simply a new flapping.cephfs-vfs list in the selftest directory which needs to be maintained. Since this doesn't change all that much, it isn't all that difficult to maintain. I expect to see more of this in the future and therefore should be fixed properly now.

To do this.

1. Add a new patch to copy flapping.ceph list to a new flapping.ceph-vfs list. This patch has to go in before we modify the file to add smb2.session.reauth4 to it.
   Other patches from this PR apply.

We then
2) patch sit-environment to user "filesystem-variant" when setting the filesystem in testinfo.yml

[anoopcs9]

1. Add a new patch to copy flapping.ceph list to a new flapping.ceph-vfs list. This patch has to go in before we modify the file to add smb2.session.reauth4 to it.
   Other patches from this PR apply.

#88 created.

[spuiuk]

ACK