dm: block: Rename device number member dev to devnum

This is a device number, and we want to use 'dev' to mean a driver model
device. Rename the member.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
diff --git a/drivers/mmc/mmc_write.c b/drivers/mmc/mmc_write.c
index 54e60db..7b186f8 100644
--- a/drivers/mmc/mmc_write.c
+++ b/drivers/mmc/mmc_write.c
@@ -68,7 +68,7 @@
 unsigned long mmc_berase(struct blk_desc *block_dev, lbaint_t start,
 			 lbaint_t blkcnt)
 {
-	int dev_num = block_dev->dev;
+	int dev_num = block_dev->devnum;
 	int err = 0;
 	u32 start_rem, blkcnt_rem;
 	struct mmc *mmc = find_mmc_device(dev_num);
@@ -174,7 +174,7 @@
 ulong mmc_bwrite(struct blk_desc *block_dev, lbaint_t start, lbaint_t blkcnt,
 		 const void *src)
 {
-	int dev_num = block_dev->dev;
+	int dev_num = block_dev->devnum;
 	lbaint_t cur, blocks_todo = blkcnt;
 	int err;