LU-11404 llite: only first sync to MDS matter

LU-11404 llite: only first sync to MDS matter

fsync() is supposed to sync metadata and data, but given file's
layout the only first MDS_SYNC matters to ensure the file creation
has been committed, everything else go to OSTs (data and attributes)
also, uid/gid/mode, EAs and ACLs must be subject to sync.

Change-Id: Iaa9095a9ace319a6dfa8840313dc536e39786847
Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/33175
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>