[Perl/perl5] 922e8c: Update perlop.pod

[積丹尼 Dan Jacobson via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: 922e8c46512ec446e49a3b89d167175d29385408
      
https://github.com/Perl/perl5/commit/922e8c46512ec446e49a3b89d167175d29385408
  Author: 積丹尼 Dan Jacobson <jida...@jidanni.org>
  Date:   2023-10-02 (Mon, 02 Oct 2023)

  Changed paths:
    M pod/perlop.pod

  Log Message:
  -----------
  Update perlop.pod

Elsewhere in the page we see
> The bottom line is that using "/o" is almost never a good idea.

So I'll get rid of /o here too.

P.S., I also get rid of a newline, based on
```
$ echo 'while(<>){}if 0;'|perltidy
while (<>) { }
if 0;
```