chore(library/simplifier): fix style warning
chore(library/simplifier): fix style warning

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

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