[PATCH] libata: kill NULL qc handling from ->eng_timeout callbacks

->eng_timeout cannot be invoked with NULL qc anymore.  Add an
assertion in ata_scsi_error() and kill NULL qc handling from all
->eng_timeout callbacks.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/scsi/libata-core.c

@@ -3524,20 +3524,10 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
 
 void ata_eng_timeout(struct ata_port *ap)
 {
-	struct ata_queued_cmd *qc;
-
 	DPRINTK("ENTER\n");
 
-	qc = ata_qc_from_tag(ap, ap->active_tag);
-	if (qc)
-		ata_qc_timeout(qc);
-	else {
-		printk(KERN_ERR "ata%u: BUG: timeout without command\n",
-		       ap->id);
-		goto out;
-	}
+	ata_qc_timeout(ata_qc_from_tag(ap, ap->active_tag));
 
-out:
 	DPRINTK("EXIT\n");
 }