[XPU] fix weight scale shape (vllm-project#42725)

Signed-off-by: Zhu, Zufang <zufang.zhu@intel.com>
Co-authored-by: Kunshang Ji <kunshang.ji@intel.com>

Author: zufangzhu

vllm/model_executor/kernels/linear/scaled_mm/xpu.py

@@ -59,6 +59,9 @@ def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
             replace_parameter(layer, "weight", weight.data.t())
         # else: already in [in, out] layout — no-op
 
+        weight_scale = layer.weight_scale.t().contiguous()
+        replace_parameter(layer, "weight_scale", weight_scale.data)
+
     def apply_weights(
         self,
         layer: torch.nn.Module,