Fixed Android STLPort related error.

Change-Id: I59ff072e526fc63b3215767a4d4a2a8944b65654

src/idl_gen_general.cpp

@@ -1784,7 +1784,7 @@ bool GenerateBinary(const Parser &parser, const std::string &path,
                     const std::string &file_name) {
   if (parser.opts.use_flexbuffers) {
     auto data_vec = parser.flex_builder_.GetBuffer();
-    auto data_ptr = reinterpret_cast<char *>(data_vec.data());
+    auto data_ptr = reinterpret_cast<char *>(data(data_vec));
     return !parser.flex_builder_.GetSize() ||
            flatbuffers::SaveFile(
                BinaryFileName(parser, path, file_name).c_str(), data_ptr,