Update ch09-02-recoverable-errors-with-result.md

[green961]

https://kaisery.github.io/trpl-zh-cn/ch09-02-recoverable-errors-with-result.html#%E5%8C%B9%E9%85%8D%E4%B8%8D%E5%90%8C%E7%9A%84%E9%94%99%E8%AF%AF

我们希望在内层 match 中检查的条件是 error.kind() 的返回值是否为 ErrorKind 的 NotFound 成员。如果是，则尝试通过 File::create 创建文件。然而因为 File::create 也可能会失败，还需要增加一个内层 match 语句。当文件不能被打开，会打印出一个不同的错误信息。外层 match 的最后一个分支保持不变，这样对任何除了文件不存在的错误会使程序 panic。

The condition we want to check in the inner match is whether the value returned by error.kind() is the NotFound variant of the ErrorKind enum. If it is, we try to create the file with File::create. However, because File::create could also fail, we need a second arm in the inner match expression. When the file can’t be created, a different error message is printed. The second arm of the outer match stays the same, so the program panics on any error besides the missing file error.