clang-format: Fix corner case in builder-type call formatting.

Before:
  return aaaaaaaaaaaaaaaa.aaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaaaaaa,
						  aaaaaaaaaaaaaaaaa)
      .aaaa(aaaaaaaaaaaaaa);

After:
  return aaaaaaaaaaaaaaaa
      .aaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaaaaaa, aaaaaaaaaaaaaaaaa)
      .aaaa(aaaaaaaaaaaaaa);

llvm-svn: 256750