UFS/FFS: Migrate to modern uintXX_t from u_intXX_t.
As per https://lists.freebsd.org/archives/freebsd-scsi/2023-July/000257.html
move to the modern uintXX_t. While here also migrate u_char to uint8_t.
Where other kernel interfaces allow, migrate u_long to uint64_t.
No functional changes intended.
Sponsored-by: The FreeBSD Foundation
(cherry picked from commit 831b1ff7913fb0b317a258a43dce5abefee03a31)