LU-15046 osp: precreate thread vs connect race

LU-15046 osp: precreate thread vs connect race

lcs_exp (required for fid client) was initialized in osp_obd_connect()
which races with osp_precreate_thread(). the latter can get stuck if
lcs_exp is not initialized and then the whole precreation logic is
blocked until remount. instead the precreation thread can just wait
preliminary until lcs_exp is initialized properly.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I7a42bf4b17ce5d46bc25bd548d81eb55f168804b
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/45099
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Sergey Cheremencev <sergey.cheremencev@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>