New comment by Phicem on void-packages repository

https://github.com/void-linux/void-packages/pull/39984#issuecomment-1304569495

Comment:
Actually I used a variable named `_FFLAGS` instead of `FFLAGS`, because an xlint warning told me to prefix custom variables with`_`. I did not realize that this change of name would make me lose the benefit of getting default FFLAGS.

I will fix this and use `FFLAGS` directly, but I'm expecting that xlint test will fail. By the way, shouln't we add `FFLAGS` to the list of official variables recognized by xlint?

(I keep this last change as a separate commit, I'll rebase if the change is okay.)