Merge tag 'drm-intel-fixes-2015-04-02' of git://anongit.freedesktop.org/drm-intel into drm-fixes

one oops fixes and a 0-length allocation fix from next backported.

* tag 'drm-intel-fixes-2015-04-02' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Reject the colorkey ioctls for primary and cursor planes
  drm/i915: Skip allocating shadow batch for 0-length batches