PTY: remove one empty ops->remove

Currently, there are two as a left-over from previous patches.
Although we really need to provide an empty handler, we do not need
two. So remove one of them.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>