Error log: Correct error type in anonymous mode (#7414)

Currently message is set to error type value.
Message field is not used in error logs. it is used only in the case of info logs.

This PR sets error message field to store error type correctly.

cmd/logger/logger.go

@@ -343,7 +343,7 @@ func logIf(ctx context.Context, err error) {
 		entry.API.Args.Bucket = hashString(entry.API.Args.Bucket)
 		entry.API.Args.Object = hashString(entry.API.Args.Object)
 		entry.RemoteHost = hashString(entry.RemoteHost)
-		entry.Message = reflect.TypeOf(err).String()
+		entry.Trace.Message = reflect.TypeOf(err).String()
 		entry.Trace.Variables = make(map[string]string)
 	}