ext4: do not check fast symlink during orphan recovery

ext4: do not check fast symlink during orphan recovery

Commit '5f920d5d6083 ("ext4: verify fast symlink length")' causes the
generic/475 test to fail during orphan cleanup of zero-length symlinks.

  generic/475  84s ... _check_generic_filesystem: filesystem on /dev/vde is inconsistent

The fsck reports are provided below:

  Deleted inode 9686 has zero dtime.
  Deleted inode 158230 has zero dtime.
  ...
  Inode bitmap differences:  -9686 -158230
  Orphan file (inode 12) block 13 is not clean.
  Failed to initialize orphan file.

In ext4_symlink(), a newly created symlink can be added to the orphan
list due to ENOSPC. Its data has not been initialized, and its size is
zero. Therefore, we need to disregard the length check of the symbolic
link when cleaning up orphan inodes. Instead, we should ensure that the
nlink count is zero.

Fixes: 5f920d5d6083 ("ext4: verify fast symlink length")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260131091156.1733648-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org