xfs_repair: replace verify_inum with libxfs inode validators

xfs_repair: replace verify_inum with libxfs inode validators

Repair uses the verify_inum function to validate inode numbers that it
finds in the superblock and in directories.  libxfs now has validator
functions to cover that kind of thing, so remove verify_inum().  As a
side bonus, this means that we will flag directories that point to the
quota/realtime metadata inodes.

This fixes a regression found by fuzzing u3.sfdir3.hdr.parent.i4 to
lastbit (aka making a directory's .. point to the user quota inode) in
xfs/384.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>