jbd2: use shrink_type type instead of bool type for __jbd2_journal_clean_checkpoint_list()

"enum shrink_type" can clearly express the meaning of the parameter of
__jbd2_journal_clean_checkpoint_list(), and there is no need to use the
bool type.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240407065355.1528580-2-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>