tty: tty_buffer: use bool for 'restart' in tty_buffer_unlock_exclusive()

It's a boolean value, so no need for 'int' there.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230919085156.1578-12-jirislaby@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>