drm/panel: lg-sw43408: add missing error handling

drm/panel: lg-sw43408: add missing error handling

Add missing error handling for the mipi_dsi_ functions that actually
return error code instead of silently ignoring it.

Fixes: 069a6c0e94f9 ("drm: panel: Add LG sw43408 panel driver")
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20240512-dsi-panels-upd-api-v2-1-e31ca14d102e@linaro.org
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240512-dsi-panels-upd-api-v2-1-e31ca14d102e@linaro.org