scsi: sd_zbc: Remove unused inline functions

These are no longer used and can be removed.

Link: https://lore.kernel.org/r/20200715025523.34620-1-yuehaibing@huawei.com


Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>