[lemmas] Refactoring in saving goal.
[lemmas] Refactoring in saving goal.

Just a cleanup, should bring no functional code change.

coq/coq,SkySkimmer/coq,Matafou/coq,SkySkimmer/coq,gares/coq,Matafou/coq,JasonGross/coq,Zimmi48/coq,Zimmi48/coq,silene/coq,Zimmi48/coq,ejgallego/coq,gares/coq,ejgallego/coq,JasonGross/coq,JasonGross/coq,coq/coq,coq/coq,gares/coq,silene/coq,SkySkimmer/coq,SkySkimmer/coq,silene/coq,gares/coq,ejgallego/coq,Matafou/coq,ejgallego/coq,gares/coq,Zimmi48/coq,coq/coq,JasonGross/coq