XCB-XVideo: no need to detach segment explicitly before disconnection

The X server will do as part of garbage collection - as it does for our
window, graphic context, or if VLC crashes.

modules/video_output/xcb/common.c

@@ -260,11 +260,8 @@ void PictureResourceFree (picture_resource_t *res, xcb_connection_t *conn)
 {
     xcb_shm_seg_t segment = res->p_sys->segment;
 
-    if (segment != 0)
-    {
-        assert (conn != NULL);
+    if (conn != NULL && segment != 0)
         xcb_shm_detach (conn, segment);
-    }
     shmdt (res->p->p_pixels);
 }
 

modules/video_output/xcb/xvideo.c

@@ -529,7 +529,7 @@ static void Close (vlc_object_t *obj)
 
             if (!res->p->p_pixels)
                 break;
-            PictureResourceFree (res, p_sys->conn);
+            PictureResourceFree (res, NULL);
         }
         picture_pool_Delete (p_sys->pool);
     }