mtd: block: use a simple bool to track open for write

Instead of propagating the fmode_t, just use a bool to track if a mtd
block device was opened for writing.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Richard Weinberger <richard@nod.at>
Link: https://lore.kernel.org/r/20230608110258.189493-23-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/mtd/mtd_blkdevs.c

@@ -208,7 +208,7 @@ static int blktrans_open(struct gendisk *disk, fmode_t mode)
 	ret = __get_mtd_device(dev->mtd);
 	if (ret)
 		goto error_release;
-	dev->file_mode = mode;
+	dev->writable = mode & FMODE_WRITE;
 
 unlock:
 	dev->open++;

drivers/mtd/mtdblock.c

@@ -294,7 +294,7 @@ static void mtdblock_release(struct mtd_blktrans_dev *mbd)
 		 * It was the last usage. Free the cache, but only sync if
 		 * opened for writing.
 		 */
-		if (mbd->file_mode & FMODE_WRITE)
+		if (mbd->writable)
 			mtd_sync(mbd->mtd);
 		vfree(mtdblk->cache_data);
 	}

include/linux/mtd/blktrans.h

@@ -34,7 +34,7 @@ struct mtd_blktrans_dev {
 	struct blk_mq_tag_set *tag_set;
 	spinlock_t queue_lock;
 	void *priv;
-	fmode_t file_mode;
+	bool writable;
 };
 
 struct mtd_blktrans_ops {