fix build warning
fix build warning

VSadov/corefxlab,ahsonkhan/corefxlab,ericstj/corefxlab,adamsitnik/corefxlab,tarekgh/corefxlab,stephentoub/corefxlab,stephentoub/corefxlab,VSadov/corefxlab,benaadams/corefxlab,tarekgh/corefxlab,dotnet/corefxlab,joshfree/corefxlab,Vedin/corefxlab,stephentoub/corefxlab,Vedin/corefxlab,VSadov/corefxlab,weshaggard/corefxlab,dotnet/corefxlab,Vedin/corefxlab,VSadov/corefxlab,ericstj/corefxlab,hanblee/corefxlab,ericstj/corefxlab,stephentoub/corefxlab,hanblee/corefxlab,ericstj/corefxlab,ahsonkhan/corefxlab,KrzysztofCwalina/corefxlab,ericstj/corefxlab,joshfree/corefxlab,Vedin/corefxlab,stephentoub/corefxlab,stephentoub/corefxlab,Vedin/corefxlab,adamsitnik/corefxlab,VSadov/corefxlab,KrzysztofCwalina/corefxlab,benaadams/corefxlab,whoisj/corefxlab,Vedin/corefxlab,ravimeda/corefxlab,alexperovich/corefxlab,whoisj/corefxlab,ericstj/corefxlab,VSadov/corefxlab