tdf#157112: fix off-by-one error in /LastChar of PDF Type 3 fonts

It should be the index of the last glyph in the subset, so nGlyphs - 1.

Change-Id: I62853a27b602d7b3e6b6265555542dd417438fcc
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/156630
Tested-by: Jenkins
Reviewed-by: خالد حسني <khaled@libreoffice.org>
diff --git a/vcl/source/gdi/pdfwriter_impl.cxx b/vcl/source/gdi/pdfwriter_impl.cxx
index ff2de85..64dfc80 100644
--- a/vcl/source/gdi/pdfwriter_impl.cxx
+++ b/vcl/source/gdi/pdfwriter_impl.cxx
@@ -2627,7 +2627,7 @@ bool PDFWriterImpl::emitType3Font(const vcl::font::PhysicalFontFace* pFace,

            "/FirstChar 0\n"
            "/LastChar "
            + OString::number(nGlyphs)
            + OString::number(nGlyphs - 1)
            + "\n"

            "/Widths[");