ext4: avoid recheck extent for EXT4_EX_FORCE_CACHE

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8UB3F



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Buffer with verified means that it has been checked before. No need
verify and call set_buffer_verified again.

Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun1@huawei.com>