[SCSI] qla2xxx: Micro optimization in queuecommand handler

Optimized queuecommand handler's to eliminate double head-room checks.
The checks are moved inside the 1st if-loop otherwise you would end up checking twice when there is
enough head room.
Signed-off-by: NChetan Loke <loke.chetan@gmail.com>
Reviewed-by: NAndrew Vasquez <andrew.vasquez@qlogic.com>
Reviewed-by: NGiridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NChad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla2xxx/qla_iocb.c

@@ -385,9 +385,10 @@ qla2x00_start_scsi(srb_t *sp)
 		else
 			req->cnt = req->length -
 			    (req->ring_index - cnt);
+		/* If still no head room then bail out */
+		if (req->cnt < (req_cnt + 2))
+			goto queuing_error;
 	}
-	if (req->cnt < (req_cnt + 2))
-		goto queuing_error;
 
 	/* Build command packet */
 	req->current_outstanding_cmd = handle;
@@ -1502,9 +1503,9 @@ qla24xx_start_scsi(srb_t *sp)
 		else
 			req->cnt = req->length -
 				(req->ring_index - cnt);
+		if (req->cnt < (req_cnt + 2))
+			goto queuing_error;
 	}
-	if (req->cnt < (req_cnt + 2))
-		goto queuing_error;
 
 	/* Build command packet. */
 	req->current_outstanding_cmd = handle;
@@ -1717,11 +1718,10 @@ qla24xx_dif_start_scsi(srb_t *sp)
 		else
 			req->cnt = req->length -
 				(req->ring_index - cnt);
+		if (req->cnt < (req_cnt + 2))
+			goto queuing_error;
 	}
 
-	if (req->cnt < (req_cnt + 2))
-		goto queuing_error;
-
 	status |= QDSS_GOT_Q_SPACE;
 
 	/* Build header part of command packet (excluding the OPCODE). */
@@ -2343,11 +2343,10 @@ qla82xx_start_scsi(srb_t *sp)
 			else
 				req->cnt = req->length -
 					(req->ring_index - cnt);
+			if (req->cnt < (req_cnt + 2))
+				goto queuing_error;
 		}
 
-		if (req->cnt < (req_cnt + 2))
-			goto queuing_error;
-
 		ctx = sp->u.scmd.ctx =
 		    mempool_alloc(ha->ctx_mempool, GFP_ATOMIC);
 		if (!ctx) {