[LTP] [RFC] Using shellcheck for shell make check

[Petr Vorel]

Hi,

checkbashisms does not detect all things: e.g. not catching {1..$FILE_COUNT}
[1]. Maybe we should reconsider using *also* shellcheck as Joerg suggested
(keep checkbashisms).

I don't like shellcheck output, but it can detects errors checkbashisms cannot
detect (checkbashisms is regexp based, but shellcheck IMHO evaluates the code).
Also it's configurable, thus ve could disable check we don't like or enable only
what we want to check. Or we can run just --severity=warning or
--severity=error. If you're not against it, I can have look into this.

Kind regards,
Petr

[1] https://lore.kernel.org/ltp/YZy5HNteJmoicTtJ@pevik/