remove unused var to fix warning from last checkin

mailnews/extensions/bayesian-spam-filter/src/nsBayesianFilter.cpp

@@ -654,7 +654,6 @@ NS_IMETHODIMP nsBayesianFilter::ClassifyMessage(const char *aMessageURL, nsIMsgW
 /* void classifyMessages (in unsigned long aCount, [array, size_is (aCount)] in string aMsgURLs, in nsIJunkMailClassificationListener aListener); */
 NS_IMETHODIMP nsBayesianFilter::ClassifyMessages(PRUint32 aCount, const char **aMsgURLs, nsIMsgWindow *aMsgWindow, nsIJunkMailClassificationListener *aListener)
 {
-    nsresult rv = NS_OK;
     TokenAnalyzer* analyzer = new MessageClassifier(this, aListener, aMsgWindow, aCount, aMsgURLs);
     if (!analyzer) return NS_ERROR_OUT_OF_MEMORY;
     TokenStreamListener *tokenListener = new TokenStreamListener(analyzer);