limit symbol visibility

Change-Id: I54d5fbe1cd9d5ae94cb134f08fc00593c802ebee
diff --git a/filter/source/msfilter/msdffimp.cxx b/filter/source/msfilter/msdffimp.cxx
index c3b4286..e13d0c3 100644
--- a/filter/source/msfilter/msdffimp.cxx
+++ b/filter/source/msfilter/msdffimp.cxx
@@ -222,10 +222,13 @@ DffPropertyReader::DffPropertyReader( const SvxMSDffManager& rMan )
    InitializePropSet( DFF_msofbtOPT );
}

bool checkSeek(SvStream &rSt, sal_uInt32 nOffset)
namespace
{
    const sal_uInt64 nMaxSeek(rSt.Tell() + rSt.remainingSize());
    return (nOffset <= nMaxSeek && rSt.Seek(nOffset) == nOffset);
    bool checkSeek(SvStream &rSt, sal_uInt32 nOffset)
    {
        const sal_uInt64 nMaxSeek(rSt.Tell() + rSt.remainingSize());
        return (nOffset <= nMaxSeek && rSt.Seek(nOffset) == nOffset);
    }
}

void DffPropertyReader::SetDefaultPropSet( SvStream& rStCtrl, sal_uInt32 nOffsDgg ) const