scsi: sd_zbc: Simplify zone full condition check

According to the ZBC (and ZAC) specification, a zone that has Zone Type set
to Conventional, must also have its Zone Condition set to "Not Write
Pointer".

Therefore, a conventional zone will never have Zone Condition set to
"Full", which means that we can omit the non-conventional prerequisite from
the zone full condition check.

Link: https://lore.kernel.org/r/20211201142821.64650-1-Niklas.Cassel@wdc.com


Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>