media: dvb-usb: gp8psk: Remove an unnecessary ternary operator

There is a ternary operator, the true or false judgement of which
is unnecessary in C language semantics.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>