Don't default-construct std::strings and then assign them.

Change-Id: I8c994d1e6a8d2ebe52eaa4f0132e0deb2ecfa5f3
diff --git a/src/java_lang_Class.cc b/src/java_lang_Class.cc
index 92fb6fa..e36e5db 100644
--- a/src/java_lang_Class.cc
+++ b/src/java_lang_Class.cc
@@ -261,7 +261,7 @@
 jobject Class_getDeclaredConstructorOrMethod(JNIEnv* env, jclass javaClass, jstring javaName,
                                              jobjectArray javaArgs) {
   Class* c = Decode<Class*>(env, javaClass);
-  std::string name = Decode<String*>(env, javaName)->ToModifiedUtf8();
+  std::string name(Decode<String*>(env, javaName)->ToModifiedUtf8());
   ObjectArray<Class>* arg_array = Decode<ObjectArray<Class>*>(env, javaArgs);
 
   Method* m = FindConstructorOrMethodInArray(c->GetDirectMethods(), name, arg_array);