More reflink tests added for smb3 to Samba

[Steve French]

Just added 20 more xfststests to the SMB3 Linux client 'buildbot'
automated tests (from the surprisingly large set of xfstests that
depend on reflink support) to Samba with vfs_btrfs (these tests were
added to the cifs-testing group on the buildbot).

I suspect that there are  about 20 more reflink related existing
xfstests that could be added fairly easily, and another ~80 that
require additional fallocate features or bugfixes or will only work on
local block devices so not appropriate for SMB3 mounts.

Continuing to make progress in improving automated testing.  Next step
is to automate some of the testing of the SMB3.1.1 POSIX extensions to
Samba

-- 
Thanks,

Steve