MFC r323157 by 323157: fix recovery information with sector sizes up to 64K.
Original commit log:
The new fsck recovery information to enable it to find backup superblocks created in revision 322297 only works on disks with sector sizes up to 4K. This update allows the recovery information to be created by newfs and used by fsck on disks with sector sizes up to 64K. Note that FFS currently limits filesystem to be mounted from disks with up to 8K sectors. Expanding this limitation will be the subject of another commit.
For example, this allows newfs to work on GELI volumes with 8K sectors.
PR: 243413
Approved by: mckusick
Relnotes: Yes