scsi: sd_zbc: Prevent zone information memory leak

scsi: sd_zbc: Prevent zone information memory leak

Make sure to always free a scsi disk zone information, even for regular
disks. This ensures that there is no memory leak, even in the case of a
zoned disk changing type to a regular disk (e.g. with a reformat using the
FORMAT WITH PRESET command or other vendor proprietary command).

To do this, rename sd_zbc_clear_zone_info() to sd_zbc_free_zone_info() and
remove sd_zbc_release_disk(). A call to sd_zbc_free_zone_info() is added to
sd_zbc_read_zones() for drives for which sd_is_zoned() returns
false. Furthermore, sd_zbc_free_zone_info() code make s sure that the sdkp
rev_mutex is never used while not being initialized by gating the cleanup
code with a a check on the zone_wp_update_buf field as it is never NULL
when rev_mutex has been initialized.

Link: https://lore.kernel.org/r/20220601062544.905141-3-damien.lemoal@opensource.wdc.com
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>