Clean up comments in InputEvent methods

Removed commented-out code regarding error handling for stdin and event processing.

src/input/input_event.cc

@@ -13,18 +13,11 @@ void
 InputEvent::insert() {
   torrent::this_thread::poll()->open(this);
   torrent::this_thread::poll()->insert_read(this);
-  // EPOLLERR/EPOLLHUP is always delivered by epoll regardless of registration;
-  // register for it so a controlling-terminal/pty hangup on stdin is dispatched
-  // to event_error() instead of aborting the whole client (see event_error()).
   torrent::this_thread::poll()->insert_error(this);
 }
 
 void
 InputEvent::remove() {
-  // The file descriptor doubles as the open-state guard, mirroring SCgiTask.
-  // event_error() may already have dropped stdin from the poll set and cleared
-  // the fd; the shutdown path (Control::cleanup) still calls remove(), and a
-  // second remove_and_close() would throw "event not found" via event_mask().
   if (!is_open())
     return;
 
@@ -46,12 +39,6 @@ InputEvent::event_write() {
 
 void
 InputEvent::event_error() {
-  // The controlling terminal/pty hung up (EPOLLERR on stdin). Drop stdin from
-  // the poll set instead of letting Poll::process() throw an internal_error and
-  // kill the client -- a regression introduced with the 0.16.13 callback/poll
-  // rework. rtorrent keeps running with no keyboard input. Once removed the
-  // event is out of the poll table, so no further event_error() is dispatched
-  // to it; clearing the fd lets the shutdown remove() no-op.
   torrent::this_thread::poll()->remove_and_close(this);
   set_file_descriptor(-1);
 }