fix: prevent crash when detecting newer updates in NCA integrity verification

- Change storage assignment from SetDataStorage() method to direct array indexing to prevent crashes when newer game updates are detected.
- The previous method was incorrectly handling storage info assignment for integrity verification layers.

Signed-off-by: Zephyron <zephyron@citron-emu.org>

src/core/file_sys/fssystem/fssystem_nca_file_system_driver.cpp

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "core/file_sys/fssystem/fssystem_aes_ctr_counter_extended_storage.h"
@@ -1251,8 +1252,8 @@ Result NcaFileSystemDriver::CreateIntegrityVerificationStorageImpl(
         R_UNLESS(last_layer_info_offset + layer_info.size <= layer_info_offset,
                  ResultRomNcaInvalidIntegrityLayerInfoOffset);
     }
-    storage_info.SetDataStorage(std::make_shared<OffsetVfsFile>(
-        std::move(base_storage), layer_info.size, last_layer_info_offset));
+    storage_info[level_hash_info.max_layers - 1] = std::make_shared<OffsetVfsFile>(
+        std::move(base_storage), layer_info.size, last_layer_info_offset);
 
     // Make the integrity romfs storage.
     auto integrity_storage = std::make_shared<IntegrityRomFsStorage>();