zbd: fix zone reset condition for verify

zbd: fix zone reset condition for verify

When data verification is requested, zbd_file_reset() resets zones only
when td->runstate is not TD_VERIFYING so that the data to read back for
verify is not wiped out. However, even when verify data to read is left,
td->runstate is not always TD_VERIFYING. When verify_backlog option is
set, or when block size is not divisor of zone size, zbd_file_reset()
can be called while td->runstate is TD_RUNNING. This causes verify
failures.

To avoid the failures, improve the check condition to reset zones in
zbd_file_reset(). On top of td->runstate, refer td->io_hist_len,
td->verify_batch and td->o.verify_backlog values to avoid zone reset.
This is same check as check_get_verify().

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Vincent Fu <vincent.fu@samsung.com>