ocfs2: clear journal dirty flag after shutdown journal

ocfs2: clear journal dirty flag after shutdown journal

Dirty flag of the journal should be cleared at the last stage of umount,
if do it before jbd2_journal_destroy(), then some metadata in uncommitted
transaction could be lost due to io error, but as dirty flag of journal
was already cleared, we can't find that until run a full fsck.  This may
cause system panic or other corruption.

Link: http://lkml.kernel.org/r/20181121020023.3034-3-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@versity.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>