staging: panel: remove duplicate code

both the misc_deregister(), parport_release() and
parport_unregister_device() is there in the module_exit function also.
detach is called from parport_unregister_driver() and by the time
detach executes misc_deregister(), parport_release() and
parport_unregister_device() has already executed marking
keypad_initialized and lcd.initialized  as false. so this part of the
code will never execute.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>