ata: libata-eh: Use ata_ncq_enabled() in ata_eh_speed_down()

In ata_eh_speed_down(), instead of hard-coding the test on the device
flags to detect if NCQ is supported and enabled, use ata_ncq_enabled().
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>

drivers/ata/libata-eh.c

@@ -1817,9 +1817,7 @@ static unsigned int ata_eh_speed_down(struct ata_device *dev,
 	verdict = ata_eh_speed_down_verdict(dev);
 
 	/* turn off NCQ? */
-	if ((verdict & ATA_EH_SPDN_NCQ_OFF) &&
-	    (dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ |
-			   ATA_DFLAG_NCQ_OFF)) == ATA_DFLAG_NCQ) {
+	if ((verdict & ATA_EH_SPDN_NCQ_OFF) && ata_ncq_enabled(dev)) {
 		dev->flags |= ATA_DFLAG_NCQ_OFF;
 		ata_dev_warn(dev, "NCQ disabled due to excessive errors\n");
 		goto done;