Device::MapBuffer ignores offset param [fixed]

[EvilTrev]

In Device.cpp, MapBuffer completely ignores offset creating issues if you are mapping a region of a buffer.

Replace with something more like this:

    VkResult Device::MapBuffer(Buffer* pBuffer, VkDeviceSize offset, VkDeviceSize size, void** ppData)
    {
		uint8_t* mem = nullptr;
		VkResult result = vmaMapMemory(m_memAllocator, pBuffer->GetAllocation(), (void**)&mem);
		if ( mem && ppData )
		{
			*ppData = ( mem + offset );
		}
		return result;
    }