[components][netdev] fix divide-by-zero in ping statistics when no reply

[r3wretrhy]

拉取/合并请求描述：(PR description)

为什么提交这份PR (why to submit this PR)

Fixes #11852.

netdev_cmd_ping() divides avg_time by received before checking that any reply came back. When every request times out (unreachable target), received stays 0 and the integer division traps, which kills the shell thread (SIGFPE on the simulator, a fault on Cortex-M).

你的解决方案是什么 (what is your solution)

Only compute the average inside the existing if (received > 0) branch, which is the only place it is printed. No other behaviour change.

请提供验证的bsp和config (provide the config and bsp)

• BSP: bsp/simulator (Linux x86-64, GCC 14, ASan as enabled by the BSP)
• .config: default simulator config (RT_USING_NETDEV, NETDEV_USING_PING). For the test I registered a local dummy netdev (UP + LINK_UP) whose ops->ping returns -RT_ETIMEOUT; that harness is not part of this PR.
• action: tested locally, see below.

Before: ping 192.0.2.1 prints four timeouts and then AddressSanitizer: FPE ... netdev_cmd_ping components/net/netdev/src/netdev.c:1428.
After: prints 4 packets transmitted, 0 received, 100% packet loss and returns to msh />. With the dummy ping returning replies, the min/max/average line is printed as before.

当前拉取/合并请求的状态 Intent for your PR

必须选择一项 Choose one (Mandatory):

• 本拉取/合并请求是一个草稿版本 This PR is for a code-review and is intended to get feedback
• 本拉取/合并请求是一个成熟版本 This PR is mature, and ready to be integrated into the repo

代码质量 Code Quality：

我在这个拉取/合并请求中已经考虑了 As part of this pull request, I've considered the following:

• 已经仔细查看过代码改动的对比 Already check the difference between PR and old code
• 代码风格正确，包括缩进空格，命名及其他风格 Style guide is adhered to, including spacing, naming and other styles
• 没有垃圾代码，代码尽量精简，不包含#if 0代码，不包含已经被注释了的代码 All redundant code is removed and cleaned up
• 所有变更均有原因及合理的，并且不会影响到其他软件组件代码或BSP All modifications are justified and not affect other components or BSP
• 对难懂代码均提供对应的注释 I've commented appropriately where code is tricky
• 代码是高质量的 Code in this PR is of high quality
• 已经使用clang-format 源码格式化工具确保格式符合RT-Thread代码规范 This PR has been formatted with clang-format and complies with RT-Thread code specification
• 如果是新增bsp, 已经添加ci检查到.github/ALL_BSP_COMPILE.json 详细请参考链接BSP自查

[github-actions]

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[github-actions]

📌 Code Review Assignment

🏷️ Tag: components

Reviewers: @Maihuanyi

Changed Files (Click to expand)

• components/net/netdev/src/netdev.c

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📊 Current Review Status (Last Updated: 2026-10-06 14:49 CST)

• ⌛ @Maihuanyi Pending Review

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[wdfk-prog]

LGTM