drm/msm: remove resv fields from msm_gem_object struct

drm/msm: remove resv fields from msm_gem_object struct

The msm_gem_object structure contains resv and _resv fields that are
no longer needed since the reservation object is now stored on
drm_gem_object. msm_atomic_prepare_fb() and msm_atomic_prepare_fb()
both referenced the wrong reservation object, and would lead to an
attempt to dereference a NULL pointer. Correct those two cases to
point to the correct reservation object.

Fixes: dd55cf6929e6 ("drm: msm: Switch to use drm_gem_object reservation_object")
Cc: David Airlie <airlied@linux.ie>
Cc: linux-arm-msm@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: freedreno@lists.freedesktop.org
Cc: Rob Herring <robh@kernel.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190513234105.7531-1-masneyb@onstation.org