Marked AppLoader_ELF, AppLoader_NCCH, and Archive_RomFS virtual functions as "override".

src/core/loader/elf.h

@@ -16,13 +16,13 @@ namespace Loader {
 class AppLoader_ELF final : public AppLoader {
 public:
     AppLoader_ELF(const std::string& filename);
-    ~AppLoader_ELF();
+    ~AppLoader_ELF() override;
 
     /**
      * Load the bootable file
      * @return ResultStatus result of function
      */
-    ResultStatus Load();
+    ResultStatus Load() override;
 
 private:
     std::string filename;