Fixes spans counters

Author: tonyredondo

agent/recorder.go

@@ -201,7 +201,7 @@ func (r *SpanRecorder) sendSpans() (error, bool) {
 			buf, err := encodePayload(payload)
 			if err != nil {
 				atomic.AddInt64(&r.stats.sendSpansKo, 1)
-				atomic.AddInt64(&r.stats.spansNotSent, int64(len(spans)))
+				atomic.AddInt64(&r.stats.spansNotSent, int64(len(batch)))
 				setLastError(err)
 				return
 			}
@@ -219,12 +219,12 @@ func (r *SpanRecorder) sendSpans() (error, bool) {
 			statusCode, err := r.callIngest(buf)
 			if err != nil {
 				atomic.AddInt64(&r.stats.sendSpansKo, 1)
-				atomic.AddInt64(&r.stats.spansNotSent, int64(len(spans)))
+				atomic.AddInt64(&r.stats.spansNotSent, int64(len(batch)))
 				atomic.AddInt64(&r.stats.testSpansNotSent, testSpans)
 				setLastError(err)
 			} else {
 				atomic.AddInt64(&r.stats.sendSpansOk, 1)
-				atomic.AddInt64(&r.stats.spansSent, int64(len(spans)))
+				atomic.AddInt64(&r.stats.spansSent, int64(len(batch)))
 				atomic.AddInt64(&r.stats.testSpansSent, testSpans)
 			}
 			if statusCode == 401 {