btrfs: use btrfs_del_item() at del_logged_dentry()

btrfs: use btrfs_del_item() at del_logged_dentry()

There's no need to use btrfs_delete_one_dir_name() at del_logged_dentry()
because we are processing a dir index key which can contain only a single
name, unlike dir item keys which can encode multiple names in case of name
hash collisions. We have explicitly looked up for a dir index key by
calling btrfs_lookup_dir_index_item() and we don't log dir item keys
anymore (since commit 339d03542484 ("btrfs: only copy dir index keys when
logging a directory")). So simplify and use btrfs_del_item() directly
instead of btrfs_delete_one_dir_name().

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>