xfs_repair: invalidate dirhash entry when junking dirent

xfs_repair: invalidate dirhash entry when junking dirent

In longform_dir2_entry_check_data, we add the directory entries we find
to the incore dirent hash table after we've validated the name but
before we're totally done checking the entry.  This sequence is
necessary to detect all duplicated names in the directory.

Unfortunately, if we later decide to junk the ondisk dirent, we neglect
to mark the dirhash entry, so if the directory gets rebuilt, it will get
rebuilt with the entry that we rejected.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>