message: Don't die() when an unknown trace-cmd options is encountered
  Log the error instead. Otherwise gpuvis stops working if trace-cmd-git
  gets updated.
diff: @@ -1221,7 +1221,7 @@ static int handle_options( tracecmd_input_t *handle )
  handle->opt_version = std::string( buf, size );
  break;
  default:
  - die( handle, "%s: unknown option %d\n", __func__, option );
  + logf( "%s: unknown option %d\n", __func__, option ) ;
  break;
  }
  