This allows for modules and other parts of the kernel to potentially
contribute to the list.
The WITNESS_BLESSED macro takes two arguments, both are names of the
locks that witness should not complain about any order problems
between them.
Caveat: modules using the WITNESS_BLESSED macro and built with
WITNESS enabled will not load on non-WITNESS kernels.
- Add definition of WITNESS_BLESSED for when WITNESS is not defined
- Add blessed witness entry for tarfs and ufs
Sponsored by: Juniper Networks, Inc.