audit: make `has_DATA?` ignore commented-out lines

Before this change, audit would detect commented-out lines
containing the string 'DATA' as if there were no commenting.
Then it could complain, e.g., problem "'DATA' was found, but no
'__END__'", which would be a false alarm in that circumstance.

Closes #32568.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>