Import commit "ubi: Fix failure attaching when vid_hdr offset equals to
(sub)page size" which did not yet make it to stable upstream Linux trees.
Fixes: #12232Fixes: #12339
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
(cherry picked from commit aad34818b50029e07ed9221ae46f9770d6e29785)