ext4: make sure fs error flag setted before clear journal error

Now, jounral error number maybe cleared even though ext4_commit_super()
failed. This may lead to error flag miss, then fsck will miss to check
file system deeply.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230307061703.245965-3-yebin@huaweicloud.com