zbd/005: Enable zonemode=zbd when zone capacity is less than zone size

zbd/005: Enable zonemode=zbd when zone capacity is less than zone size

The test case zbd/005 runs fio to issue sequential write requests with
high queue depth. This workload does not require zonemode=zbd for zones
with zone capacity same as zone length. However, when the zone has
smaller zone capacity than zone size, it issues write beyond zone
capacity and triggers write errors.

To allow fio skipping the writes beyond zone capacity, specify the option
zonemode=zbd to fio when the test target zone has zone capacity smaller
than zone size.

Also remove unused sysfs access in the test case.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>