add gocritic/ruleguard checks back again, cleanup code. (#13665)

- remove some duplicated code
- reported a bug, separately fixed in #13664
- using strings.ReplaceAll() when needed
- using filepath.ToSlash() use when needed
- remove all non-Go style comments from the codebase

Co-authored-by: Aditya Manthramurthy <donatello@users.noreply.github.com>

internal/logger/logonce.go

@@ -42,11 +42,9 @@ func (l *logOnceType) logOnceIf(ctx context.Context, err error, id interface{},
 	if prevErr == nil {
 		l.IDMap[id] = err
 		shouldLog = true
-	} else {
-		if prevErr.Error() != err.Error() {
-			l.IDMap[id] = err
-			shouldLog = true
-		}
+	} else if prevErr.Error() != err.Error() {
+		l.IDMap[id] = err
+		shouldLog = true
 	}
 	l.Unlock()
 

internal/logger/target/kafka/kafka_scram_client_contrib.go

@@ -26,13 +26,14 @@ import (
 )
 
 func initScramClient(cfg Config, config *sarama.Config) {
-	if cfg.SASL.Mechanism == "sha512" {
+	switch cfg.SASL.Mechanism {
+	case "sha512":
 		config.Net.SASL.SCRAMClientGeneratorFunc = func() sarama.SCRAMClient { return &XDGSCRAMClient{HashGeneratorFcn: KafkaSHA512} }
 		config.Net.SASL.Mechanism = sarama.SASLMechanism(sarama.SASLTypeSCRAMSHA512)
-	} else if cfg.SASL.Mechanism == "sha256" {
+	case "sha256":
 		config.Net.SASL.SCRAMClientGeneratorFunc = func() sarama.SCRAMClient { return &XDGSCRAMClient{HashGeneratorFcn: KafkaSHA256} }
 		config.Net.SASL.Mechanism = sarama.SASLMechanism(sarama.SASLTypeSCRAMSHA256)
-	} else {
+	default:
 		// default to PLAIN
 		config.Net.SASL.Mechanism = sarama.SASLMechanism(sarama.SASLTypePlaintext)
 	}