HID: logitech-dj: remove false-positive error on double queueing of delayed-work

The various functions queueing work-items do not check there already is a
work-item queued before calling schedule_work(), as such they may race
with each-other and with the re-queuing done by the delayedwork_callback
itself.

This is fine as the delayedwork_callback simply is a nop if scheduled once
too much. I've actually seen the false-positive hid_err for this trigger
in practice, so lets remove it.

While at it also remove the somewhat overzealous debugging around the
schedule_work() calls.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>