Properly use an unused-but-set-variable.  Also replace a magic number.
Appease gcc48 -Wunused-but-set-variable warnings.
__attribute__ ((__packed__)) -> __packed
__attribute__((__packed__)) -> __packed
Update a comment on a structure description. Noted by wiz a long time
ago.

does not seem to be worth bumping the date for.
Log some actual information on various failures, so you can tell
what happened.
Typo in error message.
If SCARG(uap, what) = 0, copyin() will copy (size_t)-1 bytes, and it's not
a good idea; but not proven harmful.

With the help of njoly@
register with pmf.
CID 10006930: Prevent outfile overwrite resource leak.
add notreached comment
add NOTREACHED comment
typo
Avoid NULL dereference and fix sched param conversion (at least make it
do something). Pointed out by Maxime Villard