blk-wbt: move wbt_clear_stat to common place in wbt_done

wbt_done call wbt_clear_stat no matter current stat was tracked
or not, move it to common place.
Signed-off-by: Nweiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

block/blk-wbt.c

@@ -178,12 +178,11 @@ void wbt_done(struct rq_wb *rwb, struct blk_issue_stat *stat)
 
 		if (wbt_is_read(stat))
 			wb_timestamp(rwb, &rwb->last_comp);
-		wbt_clear_state(stat);
 	} else {
 		WARN_ON_ONCE(stat == rwb->sync_cookie);
 		__wbt_done(rwb, wbt_stat_to_mask(stat));
-		wbt_clear_state(stat);
 	}
+	wbt_clear_state(stat);
 }
 
 /*