The return value of drm_atomic_get_crtc_state() needs to beHi,
checked. To avoid use of error pointer 'crtc_state' in case
of the failure.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: dec92020671c ("drm: Use the state pointer directly in planes atomic_check")
Signed-off-by: Ma Ke <make24@xxxxxxxxxxx>