libata: Use SMART LBAM/LBAH password defines

Instead of hardcoding magic values for the SMART password,
use the defines in <linux/ata.h>

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 1984fc7..3d4887d 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -639,8 +639,8 @@ int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
 	if (args[0] == ATA_CMD_SMART) { /* hack -- ide driver does this too */
 		scsi_cmd[6]  = args[3];
 		scsi_cmd[8]  = args[1];
-		scsi_cmd[10] = 0x4f;
-		scsi_cmd[12] = 0xc2;
+		scsi_cmd[10] = ATA_SMART_LBAM_PASS;
+		scsi_cmd[12] = ATA_SMART_LBAH_PASS;
 	} else {
 		scsi_cmd[6]  = args[1];
 	}