drm/i915: only flip frontbuffer if crtc is active

There is no point in flipping a buffer for a disabled crtc.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -8544,9 +8544,9 @@ static int intel_crtc_cursor_set_obj(struct drm_crtc *crtc,
 		if (old_width != width)
 			intel_update_watermarks(crtc);
 		intel_crtc_update_cursor(crtc, intel_crtc->cursor_bo != NULL);
-	}
 
-	intel_frontbuffer_flip(dev, INTEL_FRONTBUFFER_CURSOR(pipe));
+		intel_frontbuffer_flip(dev, INTEL_FRONTBUFFER_CURSOR(pipe));
+	}
 
 	return 0;
 fail_unpin: