oslib: blkzoned: add blkzoned_finish_zone() helper function

oslib: blkzoned: add blkzoned_finish_zone() helper function

Add the helper function blkzoned_finish_zone() to support zone finish
operation to zoned block devices through ioctl. This feature will be
used to change status of zones which is not yet full but does not have
enough size to write next block, so that such zones do not exceed max
active zones limit. This function does zone finish only when kernel
supports the ioctl BLKFINISHZONE. Otherwise, it does nothing. This
should be fine since the kernel without BLKFINISHZONE does not report
max active zone limit through sysfs to user space.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Vincent Fu <vincent.fu@samsung.com>