clang-format: Fix another false positive in the lambda detection.

Before:
  int i = (*b)[a] -> f();

After:
  int i = (*b)[a]->f();

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203557 91177308-0d34-0410-b5e6-96231b3b80d8