Update logger.go

Author: qclaogui

logger.go

@@ -48,7 +48,7 @@ func Init(lvl int, project string) (err error) {
 		globalLevel := zapcore.Level(lvl)
 		// High-priority output should also go to standard error, and low-priority
 		// output should also go to standard out.
-		// It is usefull for Kubernetes deployment.
+		// It is useful for Kubernetes deployment.
 		// Kubernetes interprets os.Stdout log items as INFO and os.Stderr log items
 		// as ERROR by default.
 		highPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {