[libata] sata_via: fix obvious typo

Spotted by Martin Devera.
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/sata_via.c

@@ -230,7 +230,7 @@ static int vt6420_prereset(struct ata_port *ap)
 	int online;
 
 	/* don't do any SCR stuff if we're not loading */
-	if (!ATA_PFLAG_LOADING)
+	if (!(ap->pflags & ATA_PFLAG_LOADING))
 		goto skip_scr;
 
 	/* Resume phy.  This is the old resume sequence from