jbd2: simplify journal_clean_one_cp_list()

mainline inclusion
from mainline-5.14-rc1
commit dbf2bab7
category: bugfix
bugzilla: 50788 https://gitee.com/openeuler/kernel/issues/I4DDEL
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dbf2bab7935b65689f3b39178cf87374f0334ead



---------------------------

Now that __try_to_free_cp_buf() remove checkpointed buffer or transaction
when the buffer is not 'busy', which is only called by
journal_clean_one_cp_list(). This patch simplify this function by remove
__try_to_free_cp_buf() and invoke __cp_buffer_busy() directly.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-7-yi.zhang@huawei.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>