Fix VarianceChecker's relativeVariance #33145

Job	Run time
test	55m 18s
test_non_bootstrapped	0s
test_scala2_library_tasty	0s
test_windows_fast	47m 7s
community_build_a	50m 59s
community_build_b	1h 25m 46s
community_build_c	59m 43s
MiMa	10m 47s
test_windows_full	0s
test_sbt	20m 33s
build-msi-package	0s
test_java8	0s
build-sdk-package / build	7m 59s
test-msi-package	0s
build-chocolatey-package / build	23s
test-chocolatey-package	0s
publish_nightly	0s
publish_release	0s
nightly_documentation	0s
open_issue_on_failure	0s
	5h 38m 35s

Provide feedback