[SCSI] add failure return to scsi_init_shared_tag_map()

And use it in the stex driver.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/stex.c

@@ -1108,9 +1108,8 @@ stex_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (err)
 		goto out_free_irq;
 
-	scsi_init_shared_tag_map(host, ST_CAN_QUEUE);
-	if (host->bqt == NULL) {
-		err = -ENOMEM;
+	err = scsi_init_shared_tag_map(host, ST_CAN_QUEUE);
+	if (err) {
 		printk(KERN_ERR DRV_NAME "(%s): init shared queue failed\n",
 			pci_name(pdev));
 		goto out_free_irq;

include/scsi/scsi_tcq.h

@@ -138,9 +138,10 @@ static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag)
  * @shost:	the host to share the tag map among all devices
  * @depth:	the total depth of the map
  */
-static inline void scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
+static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
 {
 	shost->bqt = blk_init_tags(depth);
+	return shost->bqt ? 0 : -ENOMEM;
 }
 
 #endif /* _SCSI_SCSI_TCQ_H */