zbd: fix write zone accounting of trim workload

zbd: fix write zone accounting of trim workload

The commit e3be810bf0fd ("zbd: Support zone reset by trim") supported
trim for zonemode=zbd by introducing the function zbd_do_io_u_trim(),
which calls zbd_reset_zone(). However, it did not call
zbd_write_zone_put() to the trim target zone, then trim operation
resulted in wrong accounting of write zones.

To fix the issue, call zbd_write_zone_put() from zbd_reset_zone(). To
cover the case to reset zones without a zbd_write_zone_put() call,
prepare another function __zbd_reset_zone(). While at it, simplify
zbd_reset_zones() by calling the modified zbd_reset_zone().

Of note is that the constifier of the argument td of do_io_u_trim() is
removed since zbd_write_zone_put() requires changes in that argument.

Fixes: e3be810bf0fd ("zbd: Support zone reset by trim")
Suggested-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Vincent Fu <vincent.fu@samsung.com>