ocfs2: fix the la space leak when unmounting an ocfs2 volume

This bug has existed since the initial OCFS2 code.  The code logic in
ocfs2_sync_local_to_main() is wrong, as it ignores the last contiguous
free bits, which causes an OCFS2 volume to lose the last free clusters of
LA window on each umount command.

Link: https://lkml.kernel.org/r/20240719114310.14245-1-heming.zhao@suse.com


Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Reviewed-by: Su Yue <glass.su@suse.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>