[patch] libsas: potential null dereference

[Dan Carpenter <error27@gmail.com>]

The "sc" variable can potentially be null here, so we have to initialize
"q" later.  This was introduced in: 70b25f890 "[SCSI] fix locking around
blk_abort_request()"

Signed-off-by: Dan Carpenter <error27@gmail.com>
---
I appologize if I sent this already.  I was having trouble with my email 
earlier today and I don't see this in my gmail outbox.

diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 8228350..96dc7d0 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -1030,7 +1030,7 @@ int __sas_task_abort(struct sas_task *task)
 void sas_task_abort(struct sas_task *task)
 {
 	struct scsi_cmnd *sc = task->uldd_task;
-	struct request_queue *q = sc->device->request_queue;
+	struct request_queue *q;
 	unsigned long flags;
 
 	/* Escape for libsas internal commands */
@@ -1046,6 +1046,7 @@ void sas_task_abort(struct sas_task *task)
 		return;
 	}
 
+	q = sc->device->request_queue;
 	spin_lock_irqsave(q->queue_lock, flags);
 	blk_abort_request(sc->request);
 	spin_unlock_irqrestore(q->queue_lock, flags);