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.

Lustre-change: https://review.whamcloud.com/54041
Lustre-commit: 133fd8b4b11a0228f71d60e3d145d93be16014c9

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I0bafb8db215a2ea004928ff36049d8f053507c6f
Reviewed-by: Zhenyu Xu <bobijam@hotmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/54651
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>