Turn two errors, which are possible to trigger only by bugs,
into assertions.

Discussed with:	mav@
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation


git-svn-id: svn+ssh://svn.freebsd.org/base/head@271169 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Document initiator-portal netmask support.

MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation


git-svn-id: svn+ssh://svn.freebsd.org/base/head@271170 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f