Pass radix head ptr along with rte to rtexpunge().
Rename rtexpunge to rt_expunge().
Remove additional fib checks from rtalloc1_fib.
It looks like current consumers are either unaware
of MRT (and uses RT_DEFAULT_FIB implicitly) or
know what thay are doing, In latter case they
will be either hit by KASSERT or ESCRH will be returned
due to NULL rnh.
Fix sysctl_ifmalist() broken in r265019.

Reported by:	Olivier Cochard-Labbé
MFC with:	r265019
Documented the pget(9) system kernel interface.

Reviewed by:	trociny, kib
MFC after:	1 week
Fix SYNOPSIS ("device if_vtnet" -> "device vtnet").

Obtained from:	DragonFlyBSD
MFC after:	3 days
Fix panic on IPv4 address removal introduced in r265279.

Reported by:	Trond Endrestøl
MFC with:	r265279
Really sort out the headers.

sys/systm.h must always come after sys/param.h.

Remove sys/types.h which should never be included together with sys/param.h.

Add sys/malloc.h for correctness even if it seems to don't be needed.

Remove more unused headers found by unusedinc (from bde@) and tested with a
universe build.

Reported by:	bde
Document r265132, addition of full(4).

Sponsored by:	The FreeBSD Foundation
Dereference man.lindev.4 macros, since the device is removed.

Sponsored by:	The FreeBSD Foundation
Wrap lindev(4) references in <literal> tags.

Sponsored by:	The FreeBSD Foundation
Document r264601, addition of if_nf10bmac(4) (with no
corresponding manual page, so <literal> tags are used).

Sponsored by:	The FreeBSD Foundation
Document r265229[1], r265249[2]:
 '-J' flag added to ps(1) [1], and top(1) [2].

Sponsored by:	The FreeBSD Foundation