Revert "btrfs: split btrfs_direct_IO to read and write part"

This reverts commit d8f3e73587ce574f7a9bc165e0db69b0b148f6f8.

The patch is a cleanup of direct IO port to iomap infrastructure,
which gets reverted.

Signed-off-by: David Sterba <dsterba@suse.com>
3 files changed