fix obdiag workflow

[xiaodong-ji]

fix obdiag workflow.

Summary

Solution Description

[Teingi]

在没有安装obdiag的情况下去执行obd obdiag 报错
如下图，可以看到在安装完OBD，没安装obdiag的时候，第一次执行任何obd obdiag命令，是会自动去下载obdiag的，但是不会自动安装，导致报错

---

Execute obddiag without installing obdiag and report an error
As shown in the figure below, you can see that when OBD is installed and obdiag is not installed, the first time you execute any obd obdiag command will automatically download obdiag, but it will not automatically install it, resulting in an error

[Teingi]

卸载obdiag后再执行报错信息不够明确: [ERROR] OBD-6003: Failed to execute obdiag function diag

复现方式

# 安装obdiag
obd tool install oceanbase-diagnostic-tool

# 卸载obdiag
obd tool uninstall oceanbase-diagnostic-tool

# 随意执行obdiag命令
obd obdiag gather log -h

[Teingi]

LGTM