chore(util/sexpr): remove unnecessary decls
chore(util/sexpr): remove unnecessary decls

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

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