LU-17499 llite: inode lock in ll_migrate()

LU-17499 llite: inode lock in ll_migrate()

should be taken after data version check as this is the
correct locking order used in another paths like lseek.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I0bafb8db215a2ea004928ff36049d8f053507c6f
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/54041
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Zhenyu Xu <bobijam@hotmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>