     const struct extent_buffer *eb, int slot,        const char *fmt, ...) {  struct btrfs_key key;  struct va_format vaf;  va_list args;   btrfs_item_key_to_cpu(eb, &key, slot);  va_start(args, fmt);   vaf.fmt = fmt;  vaf.va = &args;   btrfs_crit(fs_info,  "corrupt %s: root=%llu block=%llu slot=%d ino=%llu