softmaker-office: fix product unlock error

SoftMaker/FreeOffice collects some system information upon unlocking the
product. But in doing so, it attempts to execute /bin/ls. If the execve
syscall fails, the whole unlock procedure fails. This works around that
by rewriting /bin/ls to the proper path.

SoftMaker Office restarts itself upon some operations, such changing the
theme and unlocking. Unfortunately, we do not have control over its
environment then and it will fail with an error. Starting SoftMaker
Office from scratch will then work.

Fixes #71228