[PATCH/RFC -nxt] mtd_blkdevs: Set GENHD_FL_NO_PART

[Christoph Hellwig]

I think we need the patch below to restore the old behavior where a
partitions scan happens only for those sub-drivers that do report a
partition shift.

MTD maintainers: is this intentional that raw mtdblock does not support
partitions, but the various "FTL" modules do?

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 113f86df76038..57a22d2ebaeca 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -345,6 +345,8 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 	gd->first_minor = (new->devnum) << tr->part_bits;
 	gd->minors = 1 << tr->part_bits;
 	gd->fops = &mtd_block_ops;
+	if (!tr->part_bits)
+		gd->flags |= GENHD_FL_NO_PART;
 
 	if (tr->part_bits)
 		if (new->devnum < 26)