protoc-c: Rename 'legacy_name' to 'standalone_name'

protoc-c/main.cc

@@ -9,9 +9,9 @@ int main(int argc, char* argv[]) {
 
   std::string invocation_name = argv[0];
   std::string invocation_basename = invocation_name.substr(invocation_name.find_last_of("/") + 1);
-  const std::string legacy_name = "protoc-c";
+  const std::string standalone_name = "protoc-c";
 
-  if (invocation_basename == legacy_name) {
+  if (invocation_basename == standalone_name) {
     google::protobuf::compiler::CommandLineInterface cli;
     cli.RegisterGenerator("--c_out", &c_generator, "Generate C/H files.");
     cli.SetVersionInfo(PACKAGE_STRING);