nvme-pci: fix psdt field for single segment sgls

The shortcut for single segment SGL requests did not set the PSDT field
to mark the request as using SGLs.

Fixes: 29791057 ("nvme-pci: optimize mapping single segment requests using SGLs")
Signed-off-by: NKlaus Birkelund Jensen <klaus.jensen@cnexlabs.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

drivers/nvme/host/pci.c

@@ -830,6 +830,7 @@ static blk_status_t nvme_setup_sgl_simple(struct nvme_dev *dev,
 		return BLK_STS_RESOURCE;
 	iod->dma_len = bv->bv_len;
 
+	cmnd->flags = NVME_CMD_SGL_METABUF;
 	cmnd->dptr.sgl.addr = cpu_to_le64(iod->first_dma);
 	cmnd->dptr.sgl.length = cpu_to_le32(iod->dma_len);
 	cmnd->dptr.sgl.type = NVME_SGL_FMT_DATA_DESC << 4;