drm/drm_mode_object: fix typo in kerneldoc

Remove unintended extra word.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250204-drm-small-improvements-v4-1-d6bbc92f12f1@bootlin.com


Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>