[PATCH] fix megaraid.c locking

This fixes locking in megaraid.c, namely:

 (1) make sure megaraid_queue release the adapter lock by changing the
     code to have a single return
 (2) remove the errornous scsi_assign_lock call

Testing by Burton Windle.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Burton Windle <bwindle@fint.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/scsi/megaraid.c

@@ -380,8 +380,9 @@ megaraid_queue(Scsi_Cmnd *scmd, void (*done)(Scsi_Cmnd *))
 
 	spin_lock_irqsave(&adapter->lock, flags);
 	scb = mega_build_cmd(adapter, scmd, &busy);
+	if (!scb)
+		goto out;
 
-	if(scb) {
 	scb->state |= SCB_PENDQ;
 	list_add_tail(&scb->list, &adapter->pending_list);
 
@@ -390,13 +391,12 @@ megaraid_queue(Scsi_Cmnd *scmd, void (*done)(Scsi_Cmnd *))
 	 * delete logical drive opertion. If it is, don't run
 	 * the pending_list.
 	 */
-		if(atomic_read(&adapter->quiescent) == 0) {
+	if (atomic_read(&adapter->quiescent) == 0)
 		mega_runpendq(adapter);
-		}
-		return 0;
-	}
-	spin_unlock_irqrestore(&adapter->lock, flags);
 
+	busy = 0;
+ out:
+	spin_unlock_irqrestore(&adapter->lock, flags);
 	return busy;
 }
 
@@ -4677,7 +4677,6 @@ megaraid_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	adapter->flag = flag;
 	spin_lock_init(&adapter->lock);
-	scsi_assign_lock(host, &adapter->lock);
 
 	host->cmd_per_lun = max_cmd_per_lun;
 	host->max_sectors = max_sectors_per_io;