nvme: use the DMA_ATTR_NO_WARN attribute

Use the DMA_ATTR_NO_WARN attribute for the dma_map_sg() call of the nvme
driver that returns BLK_MQ_RQ_QUEUE_BUSY (not for BLK_MQ_RQ_QUEUE_ERROR).

Link: http://lkml.kernel.org/r/1470092390-25451-4-git-send-email-mauricfo@linux.vnet.ibm.com
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/nvme/host/pci.c

@@ -515,7 +515,8 @@ static int nvme_map_data(struct nvme_dev *dev, struct request *req,
 		goto out;
 
 	ret = BLK_MQ_RQ_QUEUE_BUSY;
-	if (!dma_map_sg(dev->dev, iod->sg, iod->nents, dma_dir))
+	if (!dma_map_sg_attrs(dev->dev, iod->sg, iod->nents, dma_dir,
+				DMA_ATTR_NO_WARN))
 		goto out;
 
 	if (!nvme_setup_prps(dev, req, size))