Fix a few syntax issues in shell scripts (#62102)

Fix a few syntax issues in shell scripts (#62102)

* Fix a few syntax issues in shell scripts

* Cleanup trailing whitespace in changed files
```sh
# git remote add dotnet https://github.com/dotnet/runtime && git pull --rebase dotnet main

if uname 2>/devnull | grep -q Darwin; then
    space=" "
fi

git show --name-only --pretty="" HEAD...dotnet/main |\
    xargs -I{} sh -c "test -f {} && sed -i$space'' 's/[[:space:]]*$//' {}"
```

* Address CR feedback