revert variable assignment hidden states shape

modeling_myolmoe.py

@@ -319,7 +319,7 @@ class MyOLMoESparseMoeBlock(nn.Module):
         
     def forward(self, hidden_states: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
         print(f"DEBUG: MoE forward start - hidden_states shape: {hidden_states.shape}")
-        batch_size, seq_len = hidden_states.shape
+        batch_size, seq_len, _ = hidden_states.shape
         hidden_states = hidden_states.view(-1, self.hidden_size)
         
         # Get routing weights and selected experts