clang-format: Improve for-loop formatting.

Before:
  for (SmallVectorImpl<TemplateIdAnnotationn *>::iterator I =
           Container.begin(),
                                                          E = Container.end();
       I != E; ++I)

After:
  for (SmallVectorImpl<TemplateIdAnnotationn *>::iterator
           I = Container.begin(),
           E = Container.end();
       I != E; ++I)

This fixes llvm.org/PR23544.

llvm-svn: 237688