fix the GetKernelTypeForVar of input for fluid.gather (#28534)

paddle/fluid/operators/gather_op.cc

@@ -69,7 +69,11 @@ class GatherOp : public framework::OperatorWithKernel {
   framework::OpKernelType GetKernelTypeForVar(
       const std::string& var_name, const framework::Tensor& tensor,
       const framework::OpKernelType& expected_kernel_type) const override {
-    return expected_kernel_type;
+    if (var_name == "Axis") {
+      return expected_kernel_type;
+    }
+    return framework::OpKernelType(expected_kernel_type.data_type_,
+                                   tensor.place(), tensor.layout());
   }
 };