fix comment

Signed-off-by: Yan Ma <yan.ma@intel.com>

Author: yma11

vllm/model_executor/layers/fused_moe/layer.py

@@ -542,7 +542,7 @@ def forward_xpu(
                 logical_to_physical_map is not None or \
                 logical_replica_count is not None:
             raise NotImplementedError("Expert load balancing is not supported "
-                                      "for CPU.")
+                                      "for XPU.")
         assert custom_routing_function is None
         return layer.ipex_fusion(
             x,