[Fontconfig] Crash with fontconfig 2.3.92

[Patrick Lam]

Frederic Crozat wrote:
> And you'll get nice crash when starting any application using
> fontconfig :)

I think I've now committed a (one-line) patch which solves this problem;
please test.  sunmoon: I wasn't comfortable with removing the iteration,
which I think needs to stay there.  However, in the iteration, I was
forgetting to bump up l as well as lp.

pat