standards/53525: getsubopt() in wrong header

[Thomas Klausner <wiz%NetBSD.org@localhost>]

>Number:         53525
>Category:       standards
>Synopsis:       getsubopt() in wrong header
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    standards-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Aug 15 04:15:00 +0000 2018
>Originator:     Thomas Klausner
>Release:        NetBSD 8.99.24
>Organization:
Curiosity is the very basis of education and if you tell me that 
curiosity killed the cat, I say only that the cat died nobly.
- Arnold Edinborough
>Environment:
	
	
Architecture: x86_64
Machine: amd64
>Description:
POSIX says that getsubopt shouldbe in stdlib.h:

http://pubs.opengroup.org/onlinepubs/9699919799/functions/getsubopt.html

On NetBSD, it is in unistd.h though:

https://nxr.netbsd.org/xref/src/include/unistd.h#358

>How-To-Repeat:
Compare the two URLs above.
>Fix:
Move the symbol to the correct header.

>Unformatted: