block: Use accessor functions for queue limits

Convert all external users of queue limits to using wrapper functions
instead of poking the request queue variables directly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

mm/bounce.c

@@ -192,7 +192,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
 		/*
 		 * is destination page below bounce pfn?
 		 */
-		if (page_to_pfn(page) <= q->bounce_pfn)
+		if (page_to_pfn(page) <= queue_bounce_pfn(q))
 			continue;
 
 		/*
@@ -284,7 +284,7 @@ void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
 	 * don't waste time iterating over bio segments
 	 */
 	if (!(q->bounce_gfp & GFP_DMA)) {
-		if (q->bounce_pfn >= blk_max_pfn)
+		if (queue_bounce_pfn(q) >= blk_max_pfn)
 			return;
 		pool = page_pool;
 	} else {