fix shape in GEMM W8A8

src/Linear.cpp

@@ -451,9 +451,9 @@ GEMM_W8A8::QuantizedActivation GEMM_W8A8::quantize(Tensor x, bool fuse_glu) {
 }
 
 Tensor GEMM_W8A8::forward_quant(QuantizedActivation qact) {
-    auto oshape = qact.act.shape;
-    oshape[-1] = out_features;
-    Tensor out = Tensor::allocate(oshape, this->dtype, qact.act.device());
+    auto shape = TensorShape(qact.act.shape.dataExtent);
+    shape[-1] = out_features;
+    Tensor out = Tensor::allocate(shape, this->dtype, qact.act.device());
     kernels::gemm_w8a8(qact.act, this->qweight, out, qact.ascales, this->wscales, this->bias);
 
     debug("gemm.out", out);