LU-17459 lod: incorrect assert in lod_statfs_and_check()

LU-17459 lod: incorrect assert in lod_statfs_and_check()

the assertion must be done once we're sure this target
has not been counted/marked as active.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I56ae3fad92b8518f6aba2c880ecdac55f53cb689
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53783
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Alexander Zarochentsev <alexander.zarochentsev@hpe.com>
Reviewed-by: Sergey Cheremencev <scherementsev@ddn.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>