[SCSI] lpfc: fix potential NULL pointer dereference in lpfc_sli4_rq_put()

The dereference to 'put_index' should be moved below the NULL test.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/lpfc/lpfc_sli.c

@@ -438,11 +438,12 @@ lpfc_sli4_rq_put(struct lpfc_queue *hq, struct lpfc_queue *dq,
 	struct lpfc_rqe *temp_hrqe;
 	struct lpfc_rqe *temp_drqe;
 	struct lpfc_register doorbell;
-	int put_index = hq->host_index;
+	int put_index;
 
 	/* sanity check on queue memory */
 	if (unlikely(!hq) || unlikely(!dq))
 		return -ENOMEM;
+	put_index = hq->host_index;
 	temp_hrqe = hq->qe[hq->host_index].rqe;
 	temp_drqe = dq->qe[dq->host_index].rqe;