ptm: create SharedExtSave file before openning it

src/core/hle/service/ptm/ptm.cpp

@@ -134,9 +134,9 @@ void Init() {
         ASSERT_MSG(archive_result.Succeeded(), "Could not open the PTM SharedExtSaveData archive!");
 
         FileSys::Path gamecoin_path("/gamecoin.dat");
+        Service::FS::CreateFileInArchive(*archive_result, gamecoin_path, sizeof(GameCoin));
         FileSys::Mode open_mode = {};
         open_mode.write_flag.Assign(1);
-        open_mode.create_flag.Assign(1);
         // Open the file and write the default gamecoin information
         auto gamecoin_result =
             Service::FS::OpenFileFromArchive(*archive_result, gamecoin_path, open_mode);