[Bugfix] Fix sync_and_slice_intermediate_tensors (#21537)

Signed-off-by: Rui Qiao <ruisearch42@gmail.com>

vllm/v1/worker/gpu_model_runner.py

@@ -1270,7 +1270,7 @@ class GPUModelRunner(LoRAModelRunnerMixin, KVConnectorModelRunnerMixin):
         if sync_self:
             assert intermediate_tensors is not None
             for k, v in intermediate_tensors.items():
-                is_scattered = "residual" and is_residual_scattered
+                is_scattered = k == "residual" and is_residual_scattered
                 copy_len = num_tokens // tp if is_scattered else \
                     num_tokens
                 self.intermediate_tensors[k][:copy_len].copy_(