[parrot/parrot] 299380: [docs] fix "Discarding return values" GH #1004

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/parrot/parrot
  Commit: 299380189134e957495e21965d83fc31ab72f744
      https://github.com/parrot/parrot/commit/299380189134e957495e21965d83fc31ab72f744
  Author: Reini Urban <rurban at cpanel.net>
  Date:   2014-03-05 (Wed, 05 Mar 2014)

  Changed paths:
    M docs/pdds/pdd19_pir.pod

  Log Message:
  -----------
  [docs] fix "Discarding return values" GH #1004

According to zefram docs/pdds/pdd19_pir.pod talks about
  sub_label($I0, $I1, $I2)
as "... discards any return values".
Actually this is not correct.
The quoted code is equivalent to

() = sub_label($I0, $I1, $I2)
It doesn't save any return values, but if result count checking is
enabled then returning any non-zero number of results will cause an
exception. Not quite the discarding that the documentation suggests.

I changed the wording to "does not save any return values."