LU-11642 lmv: allocate fid on parent MDT in migrate

LU-11642 lmv: allocate fid on parent MDT in migrate

During directory migration, if the migrated file is not directory,
the target should be allocated on its parent MDT, not user specified
MDT. Because if it's parent is striped, this file should be migrated
to the MDT by its name hash, not the starting MDT of its parent.

Add sanity 230k to check file data not changed after migration.

Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Change-Id: Ic7d3de8ea982b7cf4da758e4d3ab8d8ee15ecfdb
Reviewed-on: https://review.whamcloud.com/33641
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>