drm/msm/gem: Convert some missed GEM_WARN_ON()s

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220411215849.297838-4-robdclark@gmail.com


Signed-off-by: Rob Clark <robdclark@chromium.org>