jbd2: remove __journal_try_to_free_buffer()

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

Reference: https://lore.kernel.org/linux-ext4/20230606135928.434610-1-yi.zhang@huaweicloud.com/T/#t



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__journal_try_to_free_buffer() has only one caller and it's logic is
much simple now, so just remove it and open code in
jbd2_journal_try_to_free_buffers().

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>