[SCSI] qla2xxx: Handle IRQ-0 assignments by the system.

No restriction should be placed on the IRQ number assigned
to a given ISP.  Original code incorrectly assumed a
non-zero IRQ number assignment by the system.  In these
circumstances the proper freeing of the IRQ (via free_irq())
would not take place.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/qla2xxx/qla_def.h

@@ -2097,6 +2097,7 @@ typedef struct scsi_qla_host {
 		uint32_t	enable_lip_full_login	:1;
 		uint32_t	enable_target_reset	:1;
 		uint32_t	enable_led_scheme	:1;
+		uint32_t	inta_enabled		:1;
 		uint32_t	msi_enabled		:1;
 		uint32_t	msix_enabled		:1;
 		uint32_t	disable_serdes		:1;

drivers/scsi/qla2xxx/qla_isr.c

@@ -1725,12 +1725,14 @@ qla2x00_request_irqs(scsi_qla_host_t *ha)
 skip_msix:
 	ret = request_irq(ha->pdev->irq, ha->isp_ops.intr_handler,
 	    IRQF_DISABLED|IRQF_SHARED, QLA2XXX_DRIVER_NAME, ha);
-	if (ret) {
+	if (!ret) {
+		ha->flags.inta_enabled = 1;
+		ha->host->irq = ha->pdev->irq;
+	} else {
 		qla_printk(KERN_WARNING, ha,
 		    "Failed to reserve interrupt %d already in use.\n",
 		    ha->pdev->irq);
 	}
-	ha->host->irq = ha->pdev->irq;
 
 	return ret;
 }
@@ -1741,6 +1743,6 @@ qla2x00_free_irqs(scsi_qla_host_t *ha)
 
 	if (ha->flags.msix_enabled)
 		qla24xx_disable_msix(ha);
-	else if (ha->host->irq)
+	else if (ha->flags.inta_enabled)
 		free_irq(ha->host->irq, ha);
 }