Comment parsing: add a missing 'else'.  Found by inspection.

No testcase because we were just building an extra AST node and eventually
throwing it away, so it did not affect correctness.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170563 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed