Fix GPUTexture::GetData to properly handle volume textures

Source/Engine/GraphicsDevice/Null/GPUTextureNull.h

@@ -12,51 +12,42 @@
 class GPUTextureNull : public GPUTexture
 {
 public:
-
     // [GPUTexture]
     GPUTextureView* View(int32 arrayOrDepthIndex) const override
     {
         return nullptr;
     }
-
     GPUTextureView* View(int32 arrayOrDepthIndex, int32 mipMapIndex) const override
     {
         return nullptr;
     }
-
     GPUTextureView* ViewArray() const override
     {
         return nullptr;
     }
-
     GPUTextureView* ViewVolume() const override
     {
         return nullptr;
     }
-
     GPUTextureView* ViewReadOnlyDepth() const override
     {
         return nullptr;
     }
-
     void* GetNativePtr() const override
     {
         return nullptr;
     }
-
-    bool GetData(int32 arrayOrDepthSliceIndex, int32 mipMapIndex, TextureMipData& data, uint32 mipRowPitch) override
+    bool GetData(int32 arrayIndex, int32 mipMapIndex, TextureMipData& data, uint32 mipRowPitch) override
     {
         return true;
     }
 
 protected:
-
     // [GPUTexture]
     bool OnInit() override
     {
         return false;
     }
-
     void OnResidentMipsChanged() override
     {
     }