chore(frontends/lean/builtin_cmds): fix style
chore(frontends/lean/builtin_cmds): fix style

Kha/lean,fpvandoorn/lean,leanprover-community/lean,levnach/lean,avigad/lean,digama0/lean,fpvandoorn/lean,avigad/lean,johoelzl/lean,soonhokong/lean-osx,leanprover/lean,fgdorais/lean,fpvandoorn/lean2,UlrikBuchholtz/lean,leanprover/lean,johoelzl/lean,leanprover/lean,rlewis1988/lean,digama0/lean,fpvandoorn/lean,UlrikBuchholtz/lean,soonhokong/lean,rlewis1988/lean,javra/lean,soonhokong/lean-osx,johoelzl/lean,fpvandoorn/lean2,leanprover/lean,leodemoura/lean,fgdorais/lean,fgdorais/lean,Kha/lean,digama0/lean,javra/lean,johoelzl/lean,levnach/lean,levnach/lean,soonhokong/lean,leanprover-community/lean,johoelzl/lean,leanprover-community/lean,fgdorais/lean,fpvandoorn/lean2,rlewis1988/lean,leanprover-community/lean,avigad/lean,dselsam/lean,dselsam/lean,fpvandoorn/lean2,avigad/lean,fpvandoorn/lean,soonhokong/lean-windows,soonhokong/lean-windows,javra/lean,rlewis1988/lean,soonhokong/lean-osx,dselsam/lean,javra/lean,fpvandoorn/lean,soonhokong/lean,Kha/lean,leanprover/lean,leodemoura/lean,dselsam/lean,avigad/lean,UlrikBuchholtz/lean,fpvandoorn/lean2,soonhokong/lean-osx,UlrikBuchholtz/lean,leodemoura/lean,leanprover/lean,levnach/lean,leanprover-community/lean,leodemoura/lean,levnach/lean,UlrikBuchholtz/lean,fpvandoorn/lean,avigad/lean,dselsam/lean,johoelzl/lean,rlewis1988/lean,soonhokong/lean-osx,digama0/lean,leodemoura/lean,rlewis1988/lean,dselsam/lean,digama0/lean,fgdorais/lean,Kha/lean,leodemoura/lean,javra/lean,fgdorais/lean,Kha/lean,soonhokong/lean-windows,soonhokong/lean,soonhokong/lean,digama0/lean,soonhokong/lean-windows,Kha/lean,leanprover-community/lean,soonhokong/lean-windows