fix lscpu issue

Author: xadupre

_doc/examples/plot_benchmark_rf.py

@@ -72,8 +72,11 @@ def skl2onnx_convert_lightgbm(scope, operator, container):
 # But this information is not usually enough.
 # Let's extract the cache information.
 
-out, err = run_cmd("lscpu")
-print(out)
+try:
+    out, err = run_cmd("lscpu")
+    print(out)
+except Exception as e:
+    print("lscpu not available: {e}")
 
 ###############################################
 # Or with the following command.