[MTD] Restore MTD_ROM and MTD_RAM types

Let's not attempt the abolition of mtd->type until/unless it's properly
thought through. And certainly, let's not do it by halves.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index 1157182..0d98c22 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -324,7 +324,7 @@
 
 	dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
 	dev->mtd.erasesize = erase_size;
-	dev->mtd.type = MTD_GENERIC_TYPE;
+	dev->mtd.type = MTD_RAM;
 	dev->mtd.flags = MTD_CAP_RAM;
 	dev->mtd.erase = block2mtd_erase;
 	dev->mtd.write = block2mtd_write;