Cygwin: pty: Fix a bug on redirecting something to /dev/pty*.

- After commit 0365031ce1, key input
  becomes not working by following steps.
   1) Start cmd.exe in mintty.
   2) Open another mintty.
   3) Execute "echo AAA > /dev/pty*" (pty* is the pty opened in 1.)
  This patch fixes the issue.

winsup/cygwin/fhandler_tty.cc

@@ -969,11 +969,6 @@ fhandler_pty_slave::open (int flags, mode_t)
       init_console_handler (true);
     }
 
-  isHybrid = false;
-  get_ttyp ()->pcon_pid = 0;
-  get_ttyp ()->switch_to_pcon_in = false;
-  get_ttyp ()->switch_to_pcon_out = false;
-
   set_open_status ();
   return 1;