libata: request PHY speed configuration on SControl access failure

In sata_set_spd_needed(), if SControl read failed, it returned 0 and
skipped PHY speed configuration.  However, if SControl access fails,
it's far more logical to request PHY speed configuration.  Reverse the
logic.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

@@ -2784,7 +2784,7 @@ int sata_set_spd_needed(struct ata_link *link)
 	u32 scontrol;
 
 	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
-		return 0;
+		return 1;
 
 	return __sata_set_spd_needed(link, &scontrol);
 }