fix out of range access

this is broken since 6e4a21ff
the original commit in 2001.

I imagine the idea was to strip a trailing sal_Unicode(11) from the
end of the string and then recalculate if the string is empty, but
seeing as it has chugged away for the last 12+ years like this I'm
relunctant to change it to what it might have originally been
intended to do and instead just remove the stuff which was never
executed.

Change-Id: I73d5108ece8e716d78a4898117e0ee2d51822015

svx/source/fmcomp/dbaexchange.cxx

@@ -464,16 +464,9 @@ namespace svx
                 break;
         }
 
-        sal_Int32 nDescriptorLen = m_sCompatibleObjectDescription.getLength();
-        if (nDescriptorLen)
-        {
-            if (m_sCompatibleObjectDescription[nDescriptorLen] == 11)
-                m_sCompatibleObjectDescription = m_sCompatibleObjectDescription.copy(0, nDescriptorLen - 1);
-
-            if (nDescriptorLen)
+        if (!m_sCompatibleObjectDescription.isEmpty())
             AddFormat(SOT_FORMATSTR_ID_SBA_DATAEXCHANGE);
     }
-    }
 
     // -----------------------------------------------------------------------------
     sal_Bool ODataAccessObjectTransferable::GetData( const DataFlavor& rFlavor )