cursor: fix wrong logic when initializing the channel
cursor: fix wrong logic when initializing the channel

It's a regression introduced by commit e601e920bd5. The logic error was
introduced when trying to achieve the following code[0]. but rewritten
to prefer an early return, which was wrogly negated.

[0]:
if (cursor_is_connected(worker)
    && !COMMON_CHANNEL(worker->cursor_channel)->during_target_migrate) {
        red_channel_pipes_add_type(RED_CHANNEL(worker->cursor_channel),
                                   PIPE_ITEM_TYPE_CURSOR_INIT);
}

Signed-off-by: Fabiano Fidêncio <2931bae082ef9bc04523ba759c03a4778316d48f@redhat.com>
Acked-by: Frediano Ziglio <55d48b080b2e443e395cde84d2c83b135a4ff48e@redhat.com>

SPICE/spice,fgouget/spice,SPICE/spice,SPICE/spice,fgouget/spice,fgouget/spice,fgouget/spice