message: Clean up sched_switch event tooltip
diff: @@ -4094,14 +4094,14 @@ void TraceWin::graph_mouse_tooltip_hovered_items( std::string &ttip, graph_info_
  }
  else if ( event.is_sched_switch() )
  {
  - int prev_pid = event.pid;
  + const char *prev_comm_str = get_event_field_val( event, "prev_comm" );
  - if ( prev_pid )
  + if ( prev_comm_str[ 0 ] )
  {
  - const char *prev_pid_str = get_event_field_val( event, "prev_pid" );
  - const char *prev_comm = m_trace_events.comm_from_pid( prev_pid, prev_pid_str );
  + int prev_pid = event.pid;
  + const char *prev_comm = m_trace_events.comm_from_pid( prev_pid, prev_comm_str );
  - ttip += string_format( " %s", prev_comm );
  + ttip += string_format( " %s-%d", prev_comm, prev_pid );
  }
  }
  