Allwinner DRM changes for 4.11
Just one minor fix.
* tag 'sunxi-drm-for-4.11' of https://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux:
  drm/sun4i: Fix a return value in case of error
        DRM_DEBUG_DRIVER("Switching display backend interlaced mode %s\n",
                         interlaced ? "on" : "off");
  
 -      ret = sun4i_backend_drm_format_to_layer(plane, fb->pixel_format, &val);
 +      ret = sun4i_backend_drm_format_to_layer(plane, fb->format->format,
 +                                              &val);
        if (ret) {
                DRM_DEBUG_DRIVER("Invalid format\n");
-               return val;
+               return ret;
        }
  
        regmap_update_bits(backend->regs, SUN4I_BACKEND_ATTCTL_REG1(layer),