Make ReqInfo concurrency safe (#15204)

Some read/writes of ReqInfo did not get appropriate locks, leading to races.

Make sure reading and writing holds appropriate locks.

internal/logger/logger.go

@@ -290,6 +290,8 @@ func errToEntry(ctx context.Context, err error, errKind ...interface{}) log.Entr
 	if req == nil {
 		req = &ReqInfo{API: "SYSTEM"}
 	}
+	req.RLock()
+	defer req.RUnlock()
 
 	API := "SYSTEM"
 	if req.API != "" {