drm/connector: Add \n to message about demoting connector force-probes

The debug print clearly lacks a \n at the end. Add it.

Fixes: 8f86c82a ("drm/connector: demote connector force-probes for non-master clients")
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240502153234.1.I2052f01c8d209d9ae9c300b87c6e4f60bd3cc99e@changeid