i965/miptree: Pass the offset into create_for_bo in create_for_dri_image

Reviewed-by: Chad Versace <chadversary@chromium.org>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>

src/mesa/drivers/dri/i965/intel_mipmap_tree.c

     */
    struct intel_mipmap_tree *mt =
       intel_miptree_create_for_bo(brw, image->bo, format,
-                                  0, image->width, image->height, 1,
+                                  image->offset, image->width, image->height, 1,
                                   image->pitch,
                                   MIPTREE_LAYOUT_DISABLE_AUX);
    if (mt == NULL)
       }
    }
 
-   mt->offset = image->offset;
-
    return mt;
 }