Relax noise margin in TestOneWeightedHistogram

Signed-off-by: Mike Spreitzer <mspreitz@us.ibm.com> Kubernetes-commit: 77541c1e35e10d16787fe5951e5014195bfbf09f

Author: MikeSpreitzer

metrics/prometheusextension/weighted_histogram_test.go

@@ -99,7 +99,7 @@ func exerciseWeightedHistograms(t *testing.T, whSpecs ...weightedHistogramSpecFu
 for _, term := range terms {
 ee.sum += term
 }
-t.Logf("Adding expectation %#+v", ee)
+t.Logf("At idx=%v, adding expectation of buckets=%#+v, upperBounds=%#+v, sum=%v, count=%v", whIdx, ee.buckets, ee.upperBounds, ee.sum, ee.count)
 expectations = append(expectations, ee)
 }
 // Do the planned calls on ObserveWithWeight, in randomized order
@@ -142,8 +142,10 @@ func exerciseWeightedHistograms(t *testing.T, whSpecs ...weightedHistogramSpecFu
 actualSum := actualHist.GetSampleSum()
 num := math.Abs(actualSum - ee.sum)
 den := math.Max(math.Abs(actualSum), math.Abs(ee.sum))
-if num > den/1e14 {
-t.Errorf("At idx=%d, expected sum %v but got %v, err=%v", idx, ee.sum, actualSum, actualSum-ee.sum)
+relErr := num / den
+// Issue 120112 reports relative errors as high as 9.55994394104272e-14
+if relErr > 1e-13 {
+t.Errorf("At idx=%d, expected sum %v but got %v, err=%v, relativeErr=%v", idx, ee.sum, actualSum, actualSum-ee.sum, relErr)
 }
 }
 }