tdf#130679 Draw: Convert to polygon doesn't work

regression from
    commit 1cd32bcf1b92bd53320717626601135623dadd55
    Date:   Mon Dec 10 11:28:59 2018 +0200
    loplugin:useuniqueptr in vcl

Change-Id: I7753f54822d0249d1fcda97581051d023969fc2f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89636
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
(cherry picked from commit dc5be8f6020dd812664af250d03d2a14b9e8a3cb)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89585
diff --git a/vcl/source/gdi/impvect.cxx b/vcl/source/gdi/impvect.cxx
index bf5d2fc..d12aeab 100644
--- a/vcl/source/gdi/impvect.cxx
+++ b/vcl/source/gdi/impvect.cxx
@@ -120,7 +120,7 @@ static bool ImplColorSetCmpFnc( const ImplColorSet& lhs, const ImplColorSet& rhs
        const sal_uInt8 cLum2 = rhs.maColor.GetLuminance();
        return cLum1 < cLum2;
    }
    return lhs.mbSet < rhs.mbSet;
    return lhs.mbSet > rhs.mbSet;
}

class ImplPointArray