blk-throttle: Use more suitable time_after check for update of slice_start

There is no need to update tg->slice_start[rw] to start when they are
equal already. So remove "eq" part of check before update slice_start.
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NKemeng Shi <shikemeng@huawei.com>
Link: https://lore.kernel.org/r/20221205115709.251489-10-shikemeng@huaweicloud.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

block/blk-throttle.c

@@ -645,7 +645,7 @@ static inline void throtl_start_new_slice_with_credit(struct throtl_grp *tg,
 	 * that bandwidth. Do try to make use of that bandwidth while giving
 	 * credit.
 	 */
-	if (time_after_eq(start, tg->slice_start[rw]))
+	if (time_after(start, tg->slice_start[rw]))
 		tg->slice_start[rw] = start;
 
 	tg->slice_end[rw] = jiffies + tg->td->throtl_slice;