[perf] Increase the max value of K allowed.

This may help with detecting regressions for Skia data.

Change-Id: I4c908c7832b1e24764dfcffb58e5dc6ee110f545
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/370902
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
diff --git a/perf/go/regression/detector.go b/perf/go/regression/detector.go
index 5f7354f..b930462 100644
--- a/perf/go/regression/detector.go
+++ b/perf/go/regression/detector.go
@@ -43,7 +43,7 @@
 	// regression detections from being triggered.
 
 	// maxK is the largest K used for clustering.
-	maxK = 100
+	maxK = 200
 )
 
 // DetectorResponseProcessor is a callback that is called with RegressionDetectionResponses as a RegressionDetectionRequest is being processed.