Fix Bash integration clobbering $? for PROMPT_COMMAND

[akinomyoga]

Fixes #221393, ohmybash/oh-my-bash#595

Problem

The exit status $? that the first command of PROMPT_COMMAND sees is broken by VSCode's Bash integration. It becomes always 0 (success) even when the previous command fails. This becomes a problem for a hook in PROMPT_COMMAND that updates the prompt content PS1 based on the previous exit status. For example, this affects hooks that make the prompt green/red when the previous command succeeds/fails.

Cause

This problem was introduced by PR #208364. The exit status is supposed to be restored by the line __vsc_restore_exit_code "${__vsc_status}", but the culprit PR inserted local cmd after restoring the exit code. Then, local cmd again overwrites the exit status to 0, which PROMPT_COMMAND sees.

Solution

The line local cmd should be performed before restoring the exit status.

[Tyriar]

Thanks for looking into this, looks safe enough to merge for the upcoming release 👍