ahci: kill 'intr_status'

This field in achi_port_priv was only used to support threaded
interrupts.  Now that we are hardirq only it can be deleted.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 9e60c50b..878470f 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -309,7 +309,6 @@
 	unsigned int		ncq_saw_d2h:1;
 	unsigned int		ncq_saw_dmas:1;
 	unsigned int		ncq_saw_sdb:1;
-	atomic_t		intr_status;	/* interrupts to handle */
 	spinlock_t		lock;		/* protects parent ata_port */
 	u32 			intr_mask;	/* interrupts to enable */
 	bool			fbs_supported;	/* set iff FBS is supported */