drm/mipi-dsi: fix handling of ctx in mipi_dsi_msleep

drm/mipi-dsi: fix handling of ctx in mipi_dsi_msleep

ctx would be better off treated as a pointer to account for most of its
usage so far, and brackets should be added to account for operator
precedence for correct evaluation.

Fixes: f79d6d28d8fe ("drm/mipi-dsi: wrap more functions for streamline handling")
Signed-off-by: Tejas Vipin <tejasvipin76@gmail.com>
Suggested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240612133550.473279-3-tejasvipin76@gmail.com
[narmstrong: fixed fixes tag]
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240612133550.473279-3-tejasvipin76@gmail.com