nvme: Fix warning of cast from pointer to integer of different size

When dma_addr_t is u32 in 64-bit, there are some warnings when
building NVME driver. Fix it by doing an additional (long) cast.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c
index 1ee0a0a..d4965e2 100644
--- a/drivers/nvme/nvme.c
+++ b/drivers/nvme/nvme.c
@@ -577,7 +577,7 @@
 	int ret;
 	int shift = NVME_CAP_MPSMIN(dev->cap) + 12;
 
-	ret = nvme_identify(dev, 0, 1, (dma_addr_t)ctrl);
+	ret = nvme_identify(dev, 0, 1, (dma_addr_t)(long)ctrl);
 	if (ret)
 		return -EIO;
 
@@ -646,7 +646,7 @@
 	ns->dev = ndev;
 	/* extract the namespace id from the block device name */
 	ns->ns_id = trailing_strtol(udev->name) + 1;
-	if (nvme_identify(ndev, ns->ns_id, 0, (dma_addr_t)id))
+	if (nvme_identify(ndev, ns->ns_id, 0, (dma_addr_t)(long)id))
 		return -EIO;
 
 	flbas = id->flbas & NVME_NS_FLBAS_LBA_MASK;