drm/radeon/kms: return ret in cursor_set failure path

We were returning 0 in both the success and failure paths. Noticed while
investigating FDO bug 26403.

Signed-off-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_cursor.c

@@ -194,7 +194,7 @@ unpin:
 fail:
 	drm_gem_object_unreference_unlocked(obj);
 
-	return 0;
+	return ret;
 }
 
 int radeon_crtc_cursor_move(struct drm_crtc *crtc,