scsi: libsas: Remove postreset from sas_sata_ops

sas_sata_ops uses ata_std_postreset as .postreset callback. However,
ata_std_postreset() calls sata_scr_read()/sata_scr_write() which need to
access the ATA SCR register. This register not available in the libsas case
and the functions always return -EOPNOTSUPP.

Drop the .postreset callback.

Link: https://lore.kernel.org/r/1595408643-63011-2-git-send-email-luojiaxing@huawei.com
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/libsas/sas_ata.c

@@ -510,7 +510,6 @@ void sas_ata_end_eh(struct ata_port *ap)
 static struct ata_port_operations sas_sata_ops = {
 	.prereset		= ata_std_prereset,
 	.hardreset		= sas_ata_hard_reset,
-	.postreset		= ata_std_postreset,
 	.error_handler		= ata_std_error_handler,
 	.post_internal_cmd	= sas_ata_post_internal,
 	.qc_defer               = ata_std_qc_defer,