Merge pull request #42987 from thaJeztah/20.10_backport_create_panic_log_without_readonly

[20.10 backport] [Windows]] cmd/dockerd: create panic.log file without readonly flag

cmd/dockerd/service_windows.go

@@ -372,7 +372,7 @@ Loop:
 
 func initPanicFile(path string) error {
 	var err error
-	panicFile, err = os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0)
+	panicFile, err = os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0o200)
 	if err != nil {
 		return err
 	}