Cpp example update (#842)

* changes for CPP mnist example for cpu bug

* formatting

* one liner for input parameter

* generalizing input name

* clang format
Co-authored-by: mvermeulen <5479696+mvermeulen@users.noreply.github.com>

examples/cpp_api_inference/README.md

@@ -118,7 +118,7 @@ This directory contains everything that is needed to perform inference on an MNI
 ```
 $ mkdir build
 $ cd build
-$ cmake ..
+$ CXX=/opt/rocm/llvm/bin/clang++ cmake ..
 $ make
 ```
 There will now be an executable named `mnist_inference` in the `build` directory. This can be run with or without options. Executing without any options will produce the following output:

examples/cpp_api_inference/mnist_inference.cpp

@@ -122,10 +122,8 @@ int main(int argc, char** argv)
 
     migraphx::program_parameters prog_params;
     auto param_shapes = prog.get_parameter_shapes();
-    for(auto&& name : param_shapes.names())
-    {
-        prog_params.add(name, migraphx::argument(param_shapes[name], digit.data()));
-    }
+    auto input        = param_shapes.names().front();
+    prog_params.add(input, migraphx::argument(param_shapes[input], digit.data()));
 
     std::cout << "Model evaluating input..." << std::endl;
     auto start   = std::chrono::high_resolution_clock::now();