grovel: remove comment about the *CC* and the CC environment variable
grovel: remove comment about the *CC* and the CC environment variable

We already do look at CC in GROVEL::CC-COMPILE-AND-LINK.

3b/cffi,stassats/cffi,cffi/cffi,dkochmanski/cffi,stassats/cffi,akovalenko/cffi,dochang/cffi,dkochmanski/cffi,3b/cffi,kingcheez/cffi-cheez,akovalenko/cffi,dochang/cffi,cffi/cffi,attila-lendvai/cffi,akovalenko/cffi,wesen/cffi,wesen/cffi,mcna/cffi,wesen/cffi,3b/cffi,marsijanin/cffi,dochang/cffi,attila-lendvai/cffi,kingcheez/cffi-cheez,marsijanin/cffi,stassats/cffi,kingcheez/cffi-cheez,mcna/cffi,dkochmanski/cffi,marsijanin/cffi,cffi/cffi