Add missing trailing comma in llvm-lit.in

I was testing a stale bin/llvm-lit, which now lives at bin/llvm-lit.py
on Windows.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197446 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed