audit/kafka: Fix quitting early after first logging (#14932)

A recent commit created some regressions:
- Kafka/Audit goroutines quit when the first log is sent
- Missing doneCh initialization in Kafka audit

internal/logger/target/http/http.go

@@ -179,12 +179,14 @@ func (h *Target) startHTTPLogger() {
 	go func() {
 		defer h.wg.Done()
 
+		for {
 			select {
 			case entry := <-h.logCh:
 				h.logEntry(entry)
 			case <-h.doneCh:
 				return
 			}
+		}
 	}()
 }
 

internal/logger/target/kafka/kafka.go

@@ -96,12 +96,14 @@ func (h *Target) startKakfaLogger() {
 	go func() {
 		defer h.wg.Done()
 
+		for {
 			select {
 			case entry := <-h.logCh:
 				h.logEntry(entry)
 			case <-h.doneCh:
 				return
 			}
+		}
 	}()
 }
 
@@ -230,6 +232,7 @@ func (h *Target) Cancel() {
 func New(config Config) *Target {
 	target := &Target{
 		logCh:   make(chan interface{}, 10000),
+		doneCh:  make(chan struct{}),
 		kconfig: config,
 	}
 	return target