VideoCommon: Use GetSpanForAddress safely in texture decoding

Now only VertexLoader remains... But that one might be tricky.

Source/Core/Core/FifoPlayer/FifoPlayer.cpp

@@ -697,7 +697,7 @@ void FifoPlayer::LoadTextureMemory()
 {
   static_assert(static_cast<size_t>(TMEM_SIZE) == static_cast<size_t>(FifoDataFile::TEX_MEM_SIZE),
                 "TMEM_SIZE matches the size of texture memory in FifoDataFile");
-  std::memcpy(texMem, m_File->GetTexMem(), FifoDataFile::TEX_MEM_SIZE);
+  std::memcpy(s_tex_mem.data(), m_File->GetTexMem(), FifoDataFile::TEX_MEM_SIZE);
 }
 
 void FifoPlayer::WriteCP(u32 address, u16 value)

Source/Core/Core/FifoPlayer/FifoRecorder.cpp

@@ -291,7 +291,7 @@ void FifoRecorder::RecordInitialVideoMemory()
 
   g_main_cp_state.FillCPMemoryArray(cpmem);
 
-  SetVideoMemory(bpmem_ptr, cpmem, xfmem_ptr, xfregs_ptr, xfregs_size, texMem);
+  SetVideoMemory(bpmem_ptr, cpmem, xfmem_ptr, xfregs_ptr, xfregs_size, s_tex_mem.data());
 }
 
 void FifoRecorder::StopRecording()