LU-14642 flr: transfer layout version on layout change

LU-14642 flr: transfer layout version on layout change

After layout changed (mirror extend/split), the file's layout version
needs to transfer to OST ASAP so that following IO won't be blocked
since OFD will check its layout version stored in the xattr
XATTR_NAME_FID and find that the layout version from the client IO is
bigger (ofd_verify_layout_version()).

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: I353800e868eaf13e3c795926b0d76fb1eb45c535
Reviewed-on: https://review.whamcloud.com/43472
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Yingjin Qian <qian@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>