We skip the run_truncate_head call also for $MFT::$ATTR_BITMAP.
Otherwise wnd_map()/run_lookup_entry will not find the disk position for the bitmap parts.

Fixes: 0e5b044c ("fs/ntfs3: Refactoring attr_set_size to restore after errors")
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>