[ISSUE #7786] Optimize the execution logic of tool.sh in the JRE environment

[sevenleave]

Which Issue(s) This PR Fixes

Fixes #7786

Brief Description

修复了在jre环境下，mqadmin命令执行时，会报错JAVA_HOME未设置的错误！详情和复现，可以见 #7786
报错信息：

readlink: missing operand
Try 'readlink --help' for more information.
dirname: missing operand
Try 'dirname --help' for more information.
dirname: missing operand
Try 'dirname --help' for more information.
ERROR: Please set the JAVA_HOME variable in your environment, We need java(x64)! !!

How Did You Test This Change?

测试结果，可以见 #7786

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (3d357bb) 43.29% compared to head (54e28b6) 43.27%.
Report is 2 commits behind head on develop.

Additional details and impacted files

@@              Coverage Diff              @@
##             develop    #7787      +/-   ##
=============================================
- Coverage      43.29%   43.27%   -0.02%     
+ Complexity      9886     9878       -8     
=============================================
  Files           1173     1173              
  Lines          85049    85049              
  Branches       11015    11015              
=============================================
- Hits           36819    36804      -15     
- Misses         43658    43678      +20     
+ Partials        4572     4567       -5     

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[jiangxuhui]

rocketmq 5.3.0. no useful. the bug is still here.