kern/51200: gets considered harmful even in libsa

[dholland%netbsd.org@localhost]

>Number:         51200
>Category:       kern
>Synopsis:       gets considered harmful even in libsa
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue May 31 04:15:00 +0000 2016
>Originator:     David A. Holland
>Release:        NetBSD 7.99.30 (20160531)
>Organization:
>Environment:
n/a
>Description:

There's a gets() in libsa, in its full traditional overflowable glory.
This is really probably not such a great idea today in the era of
console servers and such, but apart from that it also causes code
scanners to light up red.

Should change it to gets_sa or something that takes a bound as well as
a buffer pointer. Hard part is testing all the affected bootbollocks.

>How-To-Repeat:

code reading

>Fix: