md/raid5-cache: removes unnecessary write-through mode judgments

The write-through mode has been returned in front of the function,
do not need to do it again.
Signed-off-by: NJackieLiu <liuyun01@kylinos.cn>
Reviewed-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NShaohua Li <shli@fb.com>

drivers/md/raid5-cache.c

@@ -2418,9 +2418,6 @@ void r5c_finish_stripe_write_out(struct r5conf *conf,
 	if (do_wakeup)
 		wake_up(&conf->wait_for_overlap);
 
-	if (conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
-		return;
-
 	spin_lock_irq(&conf->log->stripe_in_journal_lock);
 	list_del_init(&sh->r5c);
 	spin_unlock_irq(&conf->log->stripe_in_journal_lock);