EX-8190 quota: fix race in qmt_seed_glbe

EX-8190 quota: fix race in qmt_seed_glbe

There is a deadlock in qmt_pool_recalc:
The rw_semaphore "qmt_pool_info.qpi_sarr.osts.op_rw_sem" has been
acquired in qmt_pool_recalc (read mode), but it is acquired once
more in qmt_seed_glbe_all (read mode), and it will be stuck if
there is pending write mode lock acquisition.

Signed-off-by: Hongchao Zhang <hongchao@whamcloud.com>
Change-Id: Ib7db17700a90feaa9bfe8300bab509567ac1ed21
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/52346
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sergey Cheremencev <scherementsev@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>