zbd: Initialize open zones list referring zone status at fio start

zbd: Initialize open zones list referring zone status at fio start

When fio starts write workloads to zones with open status, fio does not
reflect the zone status to open zone list. This results in inconsistent
open zone accounting.

To avoid this inconsistency, initialize the open zone list referring the
zone status before workload start. If a zone in target range have open
status, call zbd_open_zone() function to build up the open zone list.
Since io_u is not available at that timing, make the function independent
from io_u. If the number of open zones exceeds maximum open zones limits,
reset the exceeding open zone by calling zbd_reset_zone().

Of note is that fio counts open zones within the write target range.
Open zones out of the range are not counted or checked.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>