ISO: Unload the iso_device on shutdown

rpcs3/Emu/System.cpp

@@ -3886,6 +3886,7 @@ void Emulator::Kill(bool allow_autoexit, bool savestate, savestate_stage* save_s
 			disc.clear();
 			klic.clear();
 			hdd1.clear();
+			unload_iso();
 			init_mem_containers = nullptr;
 			m_config_path.clear();
 			m_config_mode = cfg_mode::custom;

rpcs3/Loader/ISO.cpp

@@ -602,9 +602,12 @@ void iso_dir::rewind()
 
 void load_iso(const std::string& path)
 {
-	fs::set_virtual_device("iso_overlay_fs_dev",
-		stx::shared_ptr<iso_device>());
-
 	fs::set_virtual_device("iso_overlay_fs_dev",
 		stx::make_shared<iso_device>(path));
 }
+
+void unload_iso()
+{
+	fs::set_virtual_device("iso_overlay_fs_dev",
+		stx::shared_ptr<iso_device>());
+}

rpcs3/Loader/ISO.h

@@ -7,6 +7,7 @@ bool is_file_iso(const std::string& path);
 bool is_file_iso(const fs::file& path);
 
 void load_iso(const std::string& path);
+void unload_iso();
 
 struct iso_extent_info
 {