btrfs-progs: convert: access name_len and file_type the old way

btrfs-progs: convert: access name_len and file_type the old way

We can't use ext2_dir_entry_2 typecast on big endian machines directly.
The bytes do not get converted during extX block read due to missing
flag EXT2_DIRBLOCK_V2_STRUCT passed down to ext2fs_read_dir_block4 from
ext2fs_process_dir_block. Fixing on the ext2 side needs updating callers
and (maybe) the library interfaces. We'll fix it on the convert side for
now.

CC: Jan Kara <jack@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.cz>