Tie in the LNA diversity configuration functions into the HAL.
Turn DIAGNOSTICs to INVARIANTS in ext2fs.

This is done to be consistent with what other filesystems and
particularly ffs already does (see r173464).

MFC after:	5 days
Use CAM_DIR_NONE for requests without data.
Wrong values there confuse some drivers.

MFC after:	1 week