Pass invalid argument in valgrindTest to force failure

[eyupcanakman]

zstd with no arguments prints help and exits 0. The valgrind test harness at build/meson/tests/valgrindTest.py and its mirror in tests/Makefile assume the opposite and raise zstd without argument should have failed. Pass --parameter-does-not-exist instead so zstd exits 1 via its unknown-flag path.

Fixes #4366.

[Cyan4973]

zstd without any argument should fail (i.e. return 1), unless it's piped via stdin and stdout.
If it doesn't, it's a bug, that should be fixed.

I just tested ./zstd (no argument) on a build of the latest dev branch,
and it did fail as expected on the test system.

[eyupcanakman]

On non-TTY stdin (the valgrind subprocess case), zstd accepts input per your "piped" exception. Local check: ./programs/zstd < /dev/null > /dev/null; echo $? prints 0. --fake-stdin-is-console (@terrelln, e58a39f) lets the test simulate a console stdin so the abort fires directly. Want me to swap it in?

[Cyan4973]

yes, sounds proper

[eyupcanakman]

Swapped. Original assertion message restored.