[libata] sata_mv: fix irq port status usage

Interrupt handler did not properly initialize a variable on a per-port
basis, leading to incorrect behavior on ports other than port 0.

Bug caught and fixed by Mark Lord.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/scsi/sata_mv.c b/drivers/scsi/sata_mv.c
index aceaf56..e561281 100644
--- a/drivers/scsi/sata_mv.c
+++ b/drivers/scsi/sata_mv.c
@@ -1353,7 +1353,6 @@
 	u32 hc_irq_cause;
 	int shift, port, port0, hard_port, handled;
 	unsigned int err_mask;
-	u8 ata_status = 0;
 
 	if (hc == 0) {
 		port0 = 0;
@@ -1371,6 +1370,7 @@
 		hc,relevant,hc_irq_cause);
 
 	for (port = port0; port < port0 + MV_PORTS_PER_HC; port++) {
+		u8 ata_status = 0;
 		ap = host_set->ports[port];
 		hard_port = port & MV_PORT_MASK;	/* range 0-3 */
 		handled = 0;	/* ensure ata_status is set if handled++ */