Resolves: tdf#154915 Let empty intersection error be #NULL! instead of #REF!

Change-Id: I51f0bca8af2b283bfc72dfe75b04507c1d717014
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/150653
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Jenkins
diff --git a/sc/source/core/tool/interpr2.cxx b/sc/source/core/tool/interpr2.cxx
index cf4dde0..60bde22 100644
--- a/sc/source/core/tool/interpr2.cxx
+++ b/sc/source/core/tool/interpr2.cxx
@@ -2468,7 +2468,7 @@ void ScInterpreter::ScIntersect()
        }
        size_t n = pRefList->size();
        if (!n)
            PushError( FormulaError::NoRef);
            PushError( FormulaError::NoCode);
        else if (n == 1)
        {
            const ScComplexRefData& rRef = (*pRefList)[0];
@@ -2526,7 +2526,7 @@ void ScInterpreter::ScIntersect()
        SCROW nRow2 = ::std::min( nR2[0], nR2[1]);
        SCTAB nTab2 = ::std::min( nT2[0], nT2[1]);
        if (nCol2 < nCol1 || nRow2 < nRow1 || nTab2 < nTab1)
            PushError( FormulaError::NoRef);
            PushError( FormulaError::NoCode);
        else if (nCol2 == nCol1 && nRow2 == nRow1 && nTab2 == nTab1)
            PushSingleRef( nCol1, nRow1, nTab1);
        else