blk-iolatency: don't change the latency window

Early versions of these patches had us waiting for seconds at a time
during submission, so we had to adjust the timing window we monitored
for latency.  Now we don't do things like that so this is unnecessary
code.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-iolatency.c

@@ -468,16 +468,6 @@ static void iolatency_check_latencies(struct iolatency_grp *iolat, u64 now)
 	}
 	preempt_enable();
 
-	/*
-	 * Our average exceeded our window, scale up our window so we are more
-	 * accurate, but not more than the global timer.
-	 */
-	if (stat.mean > iolat->cur_win_nsec) {
-		iolat->cur_win_nsec <<= 1;
-		iolat->cur_win_nsec =
-			max_t(u64, iolat->cur_win_nsec, NSEC_PER_SEC);
-	}
-
 	parent = blkg_to_lat(blkg->parent);
 	if (!parent)
 		return;