Kernel: Stop creating useless Handles during object creation

They're finally unnecessary, and will stop cluttering the application's
handle table.

src/core/hle/kernel/mutex.h

@@ -22,7 +22,7 @@ public:
      * @param name Optional name of mutex
      * @return Pointer to new Mutex object
      */
-    static ResultVal<SharedPtr<Mutex>> Create(bool initial_locked, std::string name = "Unknown");
+    static SharedPtr<Mutex> Create(bool initial_locked, std::string name = "Unknown");
 
     std::string GetTypeName() const override { return "Mutex"; }
     std::string GetName() const override { return name; }