fixup last updates, and try to be better with slave ports.

the case $? needs to have the exit status of the grep, not the awk line,
so remove the awk line, it was not really helpful anyway.

Also, with slave ports, most of the time, they don't have
(PORT|DIST)VERSION, try to use CATEGORIES, PKGNAMEPREFIX or
PKGNAMESUFFIX.

PR: 211243
Submitted by: mat
Approved by: maintainer timeout
Sponsored by: Absolight