drm/atomic: fix potential null ptr on plane enable
drm/atomic: fix potential null ptr on plane enable

When a plane is being enabled, plane->crtc has not been set yet.  Use
plane->state->crtc.

Signed-off-by: Rob Clark <915c10c999604870200b6defbe633d857c856ca0@gmail.com>
Reviewed-by: Sean Paul <f9352ecf3e2294bdb914c99cca8d12601acec118@chromium.org>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs