fix(tests/util/thread): typo
fix(tests/util/thread): typo

Signed-off-by: Leonardo de Moura <7610bae85f2b530654cc716772f1fe653373e892@microsoft.com>

UlrikBuchholtz/lean,c-cube/lean,c-cube/lean,leanprover-community/lean,htzh/lean,sp3ctum/lean,fpvandoorn/lean2,Kha/lean,Kha/lean,eigengrau/lean,avigad/lean,fpvandoorn/lean2,leodemoura/lean,fpvandoorn/lean2,eigengrau/lean,avigad/lean,codyroux/lean0.1,leanprover/lean,levnach/lean,digama0/lean,fpvandoorn/lean,rlewis1988/lean,javra/lean,soonhokong/lean,Kha/lean,javra/lean,leanprover/lean,Kha/lean,avigad/lean,avigad/lean,codyroux/lean0.1,fpvandoorn/lean,rlewis1988/lean,rlewis1988/lean,dselsam/lean,fpvandoorn/lean,Kha/lean,htzh/lean,leanprover-community/lean,soonhokong/lean-osx,sp3ctum/lean,johoelzl/lean,fgdorais/lean,rlewis1988/lean,soonhokong/lean-windows,c-cube/lean,leanprover-community/lean,fgdorais/lean,soonhokong/travis_test,soonhokong/lean-osx,sp3ctum/lean,leodemoura/lean,leanprover-community/lean,soonhokong/lean-windows,eigengrau/lean,soonhokong/lean,digama0/lean,UlrikBuchholtz/lean,rlewis1988/lean,dselsam/lean,soonhokong/travis_test,htzh/lean,digama0/lean,UlrikBuchholtz/lean,sp3ctum/lean,leanprover-community/lean,soonhokong/lean-osx,levnach/lean,leodemoura/lean,dselsam/lean,soonhokong/lean,fpvandoorn/lean2,c-cube/lean,htzh/lean,leodemoura/lean,soonhokong/lean-windows,eigengrau/lean,UlrikBuchholtz/lean,UlrikBuchholtz/lean,digama0/lean,levnach/lean,javra/lean,leodemoura/lean,johoelzl/lean,c-cube/lean,johoelzl/lean,soonhokong/lean,dselsam/lean,leanprover/lean,levnach/lean,fgdorais/lean,digama0/lean,soonhokong/lean-osx,fgdorais/lean,johoelzl/lean,javra/lean,htzh/lean,leodemoura/lean,rlewis1988/lean,fgdorais/lean,soonhokong/lean-windows,soonhokong/travis_test,soonhokong/lean-windows,avigad/lean,leanprover-community/lean,fgdorais/lean,codyroux/lean0.1,leanprover/lean,fpvandoorn/lean,digama0/lean,fpvandoorn/lean,Kha/lean,eigengrau/lean,levnach/lean,dselsam/lean,soonhokong/lean-osx,johoelzl/lean,avigad/lean,leanprover/lean,dselsam/lean,codyroux/lean0.1,fpvandoorn/lean,leanprover/lean,fpvandoorn/lean2,johoelzl/lean,sp3ctum/lean,soonhokong/travis_test,javra/lean,soonhokong/lean