replace calculation to get RID_SVXERRCODE with RID_SVXERRCODE

presumably a hackaround from old deliver-headers era

Change-Id: Idbaeec7bb8523776045ce5355235a4397b2195e4
diff --git a/uui/source/iahndl-errorhandler.cxx b/uui/source/iahndl-errorhandler.cxx
index 8be4cbb..856bdef 100644
--- a/uui/source/iahndl-errorhandler.cxx
+++ b/uui/source/iahndl-errorhandler.cxx
@@ -28,6 +28,7 @@

#include <tools/errinf.hxx>
#include <svtools/svtools.hrc>
#include <svx/dialogs.hrc>

#include "ids.hrc"
#include "getcontinuations.hxx"
@@ -157,7 +158,7 @@ UUIInteractionHelper::handleErrorHandlerRequest(
                RID_CHAOS_START + 12,
                // cf. chaos/source/inc/cntrids.hrc, where
                // #define RID_CHAOS_ERRHDL (RID_CHAOS_START + 12)
                RID_SVX_START + 350, // RID_SVXERRCODE
                RID_SVXERRCODE,
                RID_UUI_ERRHDL };
        ErrCode nErrorId = nErrorCode & ~ERRCODE_WARNING_MASK;
        Source eSource = nErrorId < ERRCODE_AREA_LIB1 ?