ps: that restored aix behavior is now even more robust

ps: that restored aix behavior is now even more robust

With the commit referenced below a nasty bug affecting
aix parsing was swatted. Beyond the bug, the logic was
enhanced to disallow commas in the format string since
they would otherwise be shown with their field's data.

However, there remained many characters other than ','
that could survive the edits to then be shown adjacent
to the data. Well, with this patch they won't anymore!

[ along the way we will no longer try to forgive the ]
[ use of a double '%%' prefix since that resulted in ]
[ display of one '%' and field code instead of data. ]

Reference(s):
. March, 2022 - restored aix bahavior
commit 8cb646bdfc6e37b221f9616df96c6c116e6def28

Signed-off-by: Jim Warner <james.warner@comcast.net>