Update path after dupe fix

eng/sdl-tsa-vars.config

@@ -9,4 +9,4 @@
 -TsaCodebaseName AspNetCore
 -TsaOnboard $True
 -TsaPublish $True
--PoliCheckAdditionalRunConfigParams @("UserExclusionPath < $(Build.SourcesDirectory)/aspnetcore/eng/PoliCheckExclusions.xml")
+-PoliCheckAdditionalRunConfigParams @("UserExclusionPath < $(Build.SourcesDirectory)/s/eng/PoliCheckExclusions.xml")