xfs_repair: Fix root inode's parent when it's bogus for sf directory

xfs_repair: Fix root inode's parent when it's bogus for sf directory

Currently when root inode is in short-form and its parent ino
has an invalid value, process_sf_dir2() ends up not fixing it,
because if verify_inum() fails we never get to the next case which
would fix the root inode's parent pointer.

This behavior triggers the following assert on process_dir2():

   ASSERT((ino != mp->m_sb.sb_rootino && ino != *parent) ||
        (ino == mp->m_sb.sb_rootino &&
        (ino == *parent || need_root_dotdot == 1)));

This patch fixes this behavior by making sure we always properly
handle rootino parent pointer in process_sf_dir2()

Signed-off-by: Marco Benatto <mbenatto@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>