sd_zbc: clear zone resources for non-zoned case

For host-aware ZBC disk, setting the device zoned model to BLK_ZONED_HA
using blk_queue_set_zoned() in sd_read_block_characteristics() may
result in the block device effective zoned model to be "none"
(BLK_ZONED_NONE) if partitions are present on the device. In this case,
sd_zbc_read_zones() should not setup the zone related queue limits for
the disk so that the device limits and configuration is consistent with
a regular disk and resources not uselessly allocated (e.g. the zone
write pointer tracking array for zone append emulation).

Furthermore, if the disk zoned model changes at run time due to the
creation of a partition by the user, the zone related resources can be
released.

Fix both problems by introducing the function sd_zbc_clear_zone_info()
to reset the scsi disk zone information and free resources and by
returning early in sd_zbc_read_zones() for a block device that has a
zoned model equal to BLK_ZONED_NONE.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@edc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>