jbd2: remove t_checkpoint_io_list

maillist inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I70WHL

Reference: https://lore.kernel.org/linux-ext4/20230531115100.2779605-1-yi.zhang@huaweicloud.com/T/#t



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Since t_checkpoint_io_list was stop using in jbd2_log_do_checkpoint()
now, it's time to remove the whole t_checkpoint_io_list logic.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Conflits:
	include/linux/jbd2.h
	[ Don't remove t_checkpoint_io_list for KABI broken. ]
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>