nPDescPos is never read

...since b48f4e99e1d2935f84bc2fac1e6670dd83939673 "#86296# use page descriptor
only if necessary", and this nicely removes the odd

  for(i = 0; i < nPDescCount + 1; i++)

loop that read past the end of the maPageDescs vector.

Change-Id: I9b0f24231774eef7231eff4b053fd56c020c6e69
(cherry picked from commit 7fb6ae28ae7bebd67c2b9bf2cf517f1f7bb2777e)
Reviewed-on: https://gerrit.libreoffice.org/8003
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>