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

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

Fix reading of empty fifolog files. When we don't have anything
to inflate, skip the rest of the fifolog reader code to avoid
hitting the assert about Z_OK a bit further down.

Approved by: phk
MFC after: 1 week

Do not attempt to render a logrecord with length byte, until we have
decompressed all the bytes required.

The last sector in the first segment might just be a sync, increment before
checking validity of segment two.

Fix a cornercase during search

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.