block: move fs/block_dev.c to block/bdev.c

Move it together with the rest of the block layer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210907141303.1371844-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/internal.h b/fs/internal.h
index 68a2ae0..3cd065c 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -18,7 +18,7 @@ struct user_namespace;
 struct pipe_inode_info;
 
 /*
- * block_dev.c
+ * block/bdev.c
  */
 #ifdef CONFIG_BLOCK
 extern void __init bdev_cache_init(void);