Fix compile error

Waveform/WaveDigiTools/WaveDigiTools/IWaveformDigitisationTool.icc

@@ -39,6 +39,7 @@ StatusCode IWaveformDigitisationTool::digitise(const CONT* hitCollection,
     for (const auto& c : counts) {
       int value = baseline - c.second;
       if (value < 0) {
+	MsgStream log(&(*m_msgSvc), name());
 	log << MSG::WARNING << "Found pulse " << c.second << " larger than baseline " << c.first << endmsg;
 	value = 0; // Protect against scaling signal above baseline
       }