ksud: Return the complete error when metamodule script exec failed

[Tools-cx-app]

I think that when a meta module's meta mount fails, it should return a full err instead of an exit status, as this makes debugging difficult.

[5ec1cff]

It is recommended to redirect stdout and stderr to files (e.g., /data/adb/ksu/log/metamodule_{mount,uninstall}_{stdout,stderr}.log), and it would be best to add a switch for this feature, as it is a debugging feature.

[Tools-cx-app]

It is recommended to redirect stdout and stderr to files (e.g., /data/adb/ksu/log/metamodule_{mount,uninstall}_{stdout,stderr}.log), and it would be best to add a switch for this feature, as it is a debugging feature.

Completed