Tidy up the login code; no functional changes.

MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Make the initiator-name and initiator-portal checks a little nicer.

MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Improve ctld.conf example.

MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Fix displaying non-contiguous netmasks.

Found by:	ae
Sponsored by:	Yandex LLC
Remove redundant check and m_pullup() call.
Bump default dynamic limit to 16k entries.
Print better log message when limit is hit.

PR:		193300
Submitted by:	me at nileshgr.com
Add D-Link DWA-123 rev D1 and Elecom WDC-150SU2M.
Accept the documented FDT compatible string for the PL310 cache controller
as well as the non-standard string we've been using for a couple years.