tests: Fix example command in comment
tests: Fix example command in comment

In bash `{1-8}` isn't a valid brace-expansion so it is passed through
literally. On the other hand `{1..8}` is expanded to `1 2 3 4 5 6 7 8`.

stb-tester/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester