btrfs_del_root_ref calls btrfs_search_slot and reads name from root_ref.
Call btrfs_is_name_len_valid before memcmp.
Signed-off-by: NSu Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>