MFC r305812:

fifolog(1): invert order of calloc(3) arguments.

The second argument to calloc(3) should be the size, make it so.

While here be a little bit more cautious in fifolog_reader_open()
to protect in the unlikely event of an overflowed allocation.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Another couple of unsigned/ssize_t changes.

Update fifolog internals to match main version:

Rename ...write_bytes... to ...write_records..., that's what they do.

Move writer .h stuff into writer private .h file.

Change logic in writer to support both fifolog usage in FreeBSD and
Measured usage better, by always using an input buffer.

Various cleanups.

Fix a bunch of trivial whitespace mistakes and update the miniobj.h
file before the real work starts.

Use a "push" strategy to get data through libz, rather than a "pull" strategy.

Don't overwrite it, if only one sector is written yet.

Discovered by: "Dewayne Geraghty" <dewayne.geraghty@heuristicsystems.com.au>

Fix two bugs introduced in conversion to FreeBSD source tree:

Off by one error in length calcuation of string records.
Don't attempt to free stack variable.

Add the fifolog tools to FreeBSD.

Quoth the man-page:

Fifologs provide a compact round-robin circular storage for recording
text and binary information to permanent storage in a bounded and pre-
dictable fashion, time and space wise.

Not yet connected to the build, but feel free to test & review.