There's a lot of code under BTRFS_COMPAT_SEND_NO_UUID_TREE to support
kernels < 3.12 that don't have uuid tree and the subvolume uuids are
searched in a slow way, building the uuid tree on the userspace side.
As the uuid tree is always created, the fallback code was not exercised
anyway due to 'uuid_tree_existed' check in subvol_uuid_search2.
Delete the code from the internal copy of send-utils. The support still
stays for libbtrfs and will be removed in the future.
Signed-off-by: David Sterba <dsterba@suse.com>
