Revert "drm/i915: Avoid stalling on pending flips for legacy cursor updates"

This reverts commit acf4e84d.
Unfortunately this breaks the next commit with a use-after-free, so
temporarily revert until we can apply a solution.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463490484-19540-8-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>

drivers/gpu/drm/i915/intel_display.c

@@ -13395,9 +13395,6 @@ static int intel_atomic_prepare_commit(struct drm_device *dev,
 	}
 
 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
-		if (state->legacy_cursor_update)
-			continue;
-
 		ret = intel_crtc_wait_for_pending_flips(crtc);
 		if (ret)
 			return ret;