iOS, void unused paramters.

Change-Id: I60b7d1a49d9e9073470ee8d0d6e68b34cdd0bdad
diff --git a/vcl/source/filter/ipdf/pdfread.cxx b/vcl/source/filter/ipdf/pdfread.cxx
index 572a4c2..7f31e0a 100644
--- a/vcl/source/filter/ipdf/pdfread.cxx
+++ b/vcl/source/filter/ipdf/pdfread.cxx
@@ -195,6 +195,10 @@ bool getCompatibleStream(SvStream& rInStream, SvStream& rOutStream, sal_uInt64 n
size_t generatePreview(SvStream&, std::vector<Bitmap>&, sal_uInt64 nPos, sal_uInt64 nSize,
                       size_t nFirstPage = 0, int nLastPage = 0)
{
    (void)nPos;
    (void)nSize;
    (void)nFirstPage;
    (void)nLastPage;
    return false;
}