fix(lua/name): fix memory leak
fix(lua/name): fix memory leak

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

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